ACT English Quiz: Verb Tense
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Verb TenseQuestion 1 of 20

PASSAGE I: The Invisible Art of Noise

¹ When watching a movie, audiences usually focus on the actors' dialogue or the sweeping musical score. Rarely do they consider the crunch of footsteps in snow, the rustle of a silk dress, or the squeak of a saddle. Most viewers assume these sounds were recorded on set during filming. In reality, however, microphones are designed to pick up dialogue, not background noise. Most of the detailed sounds you hear (1) has been created weeks later in a studio by a specialized craftsperson known as a Foley artist.

² Named after Jack Foley, a sound editor at Universal Studios in the 1920s, the profession requires a unique blend of creativity and athleticism. Foley artists work on specialized stages containing recessed areas called "Foley pits." These pits hold different surfaces—gravel, dirt, hardwood, and more—that mimic real-world textures. To recreate the sound of a character walking, the artist watches the screen and mimics the actor's steps, (2) wearing the shoes that match the character's footwear. If the character is walking on broken glass, the artist steps on scattered ceramic tiles. (3) Having carefully selected the proper materials, the realistic sound is created.

³ The work involves more than just footsteps. Foley artists must be inventive to (4) generate sounds that do not exist in the real world. For a science fiction film, the sound of an alien egg hatching (5) might be created by squishing a honeydew melon. (6) On the other hand, the bone-crunching impact of a fistfight is often simulated by breaking stalks of celery or snapping carrots wrapped in a towel. The goal is realistic audio, even if the source is decidedly artificial.

⁴ Precision is critical. The sound must sync perfectly with the visual action. If a sword is drawn from a sheath one second too late, the illusion is shattered. Foley artists often perform "wild tracks," recording sounds without watching the picture, (7) but for complex scenes, they must perform in real-time, matching their movements to the actor's rhythm.

⁵ Despite their importance, Foley artists often go unrecognized. Their work is successful only when it goes unnoticed. If the audience realizes the sound of a horse's hooves is actually (8) two halves of a coconut shell being banged together, the magic is lost. Like a magician's trick, the art of Foley relies on misdirection.

⁶ Today, digital libraries offer thousands of pre-recorded sound effects. Many directors still prefer the custom touch of a human artist. A canned sound effect is static and repetitive, (9) whereas a Foley performance is organic. It breathes life into the visual image, giving weight and texture to the world on screen. (10) The next time you watch an old horror movie, remember that someone might be standing in a studio, slowly twisting an old rusty hinge.(11)

Which of the following choices makes the sentence most grammatically acceptable?

NO CHANGE
might of been created
could of been created
might be creating
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ACT English Quiz

ACT English Quiz: Verb Tense

Practice Verb Tense in ACT English with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Verb Tense, giving you a quick way to practice the rules, question types, and explanations that matter most for ACT English.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

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Question 1

PASSAGE I: The Invisible Art of Noise

¹ When watching a movie, audiences usually focus on the actors' dialogue or the sweeping musical score. Rarely do they consider the crunch of footsteps in snow, the rustle of a silk dress, or the squeak of a saddle. Most viewers assume these sounds were recorded on set during filming. In reality, however, microphones are designed to pick up dialogue, not background noise. Most of the detailed sounds you hear (1) has been created weeks later in a studio by a specialized craftsperson known as a Foley artist.

² Named after Jack Foley, a sound editor at Universal Studios in the 1920s, the profession requires a unique blend of creativity and athleticism. Foley artists work on specialized stages containing recessed areas called "Foley pits." These pits hold different surfaces—gravel, dirt, hardwood, and more—that mimic real-world textures. To recreate the sound of a character walking, the artist watches the screen and mimics the actor's steps, (2) wearing the shoes that match the character's footwear. If the character is walking on broken glass, the artist steps on scattered ceramic tiles. (3) Having carefully selected the proper materials, the realistic sound is created.

³ The work involves more than just footsteps. Foley artists must be inventive to (4) generate sounds that do not exist in the real world. For a science fiction film, the sound of an alien egg hatching (5) might be created by squishing a honeydew melon. (6) On the other hand, the bone-crunching impact of a fistfight is often simulated by breaking stalks of celery or snapping carrots wrapped in a towel. The goal is realistic audio, even if the source is decidedly artificial.

⁴ Precision is critical. The sound must sync perfectly with the visual action. If a sword is drawn from a sheath one second too late, the illusion is shattered. Foley artists often perform "wild tracks," recording sounds without watching the picture, (7) but for complex scenes, they must perform in real-time, matching their movements to the actor's rhythm.

⁵ Despite their importance, Foley artists often go unrecognized. Their work is successful only when it goes unnoticed. If the audience realizes the sound of a horse's hooves is actually (8) two halves of a coconut shell being banged together, the magic is lost. Like a magician's trick, the art of Foley relies on misdirection.

⁶ Today, digital libraries offer thousands of pre-recorded sound effects. Many directors still prefer the custom touch of a human artist. A canned sound effect is static and repetitive, (9) whereas a Foley performance is organic. It breathes life into the visual image, giving weight and texture to the world on screen. (10) The next time you watch an old horror movie, remember that someone might be standing in a studio, slowly twisting an old rusty hinge.(11)

Which of the following choices makes the sentence most grammatically acceptable?

  1. NO CHANGE (correct answer)
  2. might of been created
  3. could of been created
  4. might be creating

Explanation: This is a verb-form question, and two rules settle it. First, 'of' is a preposition and can never be part of a verb phrase, so 'might of been created' and 'could of been created' are both non-grammatical; they come from mishearing the spoken contractions 'might've' and 'could've.' Second, the sounds are acted upon rather than acting, so a passive verb is required, which is why 'might be creating' fails: it says the sounds are doing the creating, when the passage credits 'a specialized craftsperson known as a Foley artist.' The original 'has been created' is the only option that is both a well-formed verb phrase and passive, so keeping 'has been created' is correct. Whenever you see 'of' following a modal like 'might,' 'could,' or 'would,' eliminate that choice on sight.

Question 2

By the time the bus finally reached the trailhead this morning, the sky had cleared and the hikers were eager to start. Our guide explained the route and pointed out where the path narrowed near the creek. After the first mile, we stopped for water, and I realized I left my map on the seat of the bus.

  1. NO CHANGE
  2. had left my map on the seat (correct answer)
  3. have left my map on the seat
  4. will leave my map on the seat

Explanation: This question tests past perfect tense for an action discovered to have happened earlier. The time marker "By the time" and past context establish the sequence: leaving the map happened before realizing it during the hike. The correct answer is B ("had left my map") because past perfect shows the leaving occurred before the realization. Choice A uses simple past, which doesn't emphasize the time relationship as clearly. When you realize or discover something about an earlier action, past perfect clarifies the sequence.

Question 3

Last Saturday, my cousin and I visited the city museum, which was offering free admission for one day only. We started in the ancient pottery exhibit, then moved upstairs to a gallery of modern murals. After two hours, we were tired but happy because we see nearly every room on the main floor before the doors closed at 5 p.m.

  1. NO CHANGE
  2. had seen nearly every room on the main floor (correct answer)
  3. have seen nearly every room on the main floor
  4. will see nearly every room on the main floor

Explanation: This question tests past perfect versus simple past tense in a past narrative. The time markers "Last Saturday" and "before the doors closed at 5 p.m." establish a completed past timeframe. The correct answer is B ("had seen nearly every room") because past perfect shows the seeing was completed before the doors closed. Choice A incorrectly uses simple present ("see"), while C uses present perfect ("have seen"), neither of which fits the past context. Remember that past perfect emphasizes completion of one past action before another past moment.

Question 4

Earlier this week, I started reading a mystery novel that my friend recommended. Each night, I read a few chapters before bed, trying not to skip ahead. By last night, I have guessed the identity of the thief, but I kept reading to find out how the detective would prove it.

  1. NO CHANGE
  2. had guessed the identity of the thief (correct answer)
  3. guessed the identity of the thief
  4. will have guessed the identity of the thief

Explanation: This question tests past perfect tense in a narrative about reading progress. The time markers show progression: "Earlier this week" (started), "Each night" (ongoing), and "By last night" (completion point). The correct answer is B ("had guessed the identity") because past perfect shows the guessing was complete by last night, before continuing to read. Choice A incorrectly uses present perfect ("have guessed"), which doesn't fit the past narrative. Use past perfect with "by" + past time to show completion before that point.

Question 5

They had finished the project before the deadline.

  1. NO CHANGE (correct answer)
  2. finish
  3. finished
  4. were finishing

Explanation: This question tests the distinction between past perfect and other past tenses. The context indicates that the finishing occurred before the deadline, showing one past action completed before another past time reference. Past perfect 'had finished' correctly expresses an action completed before a past deadline. The other options don't establish this temporal relationship: 'finish' is present/base form, 'finished' is simple past without the 'before' relationship, and 'were finishing' is past continuous. Use past perfect (had + past participle) when one past action was completed before another past time or event.

Question 6

PASSAGE I: The First Ferris Wheel

¹ In 1889, organizers of the upcoming World's Columbian Exposition in Chicago faced a monumental (1) challenge, they wanted to construct an architectural marvel that would rival the Eiffel Tower. The Parisian tower had been the centerpiece of the 1889 World's Fair, and Chicago wanted to outdo it. Numerous architects submitted plans, but most were simply unoriginal (2) knockoffs of the Eiffel Tower. It wasn't until a thirty-three-year-old engineer named George Washington Gale Ferris Jr. pitched his (3) idea, that the organizers found their masterpiece. Ferris proposed a massive rotating wheel that would carry passengers high above the city.

² The organizers were initially skeptical. They feared the giant wheel would collapse under its own (4) weight, however, Ferris was a bridge builder who understood structural steel. He spent $25,000 of his own money on safety studies and (5) has secured financial backing from private investors. Impressed by his dedication, the exposition committee finally granted him permission to build.

³ The construction of the Ferris wheel was an unprecedented engineering feat. The wheel's axle, (6) which weighed 71 tons, was the largest piece of forged steel ever manufactured at the time. Two 140-foot steel towers supported the axle. Extending from the axle were 36 spokes, holding the massive outer rim in place. Instead of simple open-air benches, the wheel featured 36 fully enclosed wooden cars, each capable of holding 60 (8) people, as a result, a single ride could accommodate over 2,000 passengers. (7)

⁴ When the wheel officially opened to the public in June 1893, it was an instant sensation. For fifty cents, riders were lifted 264 feet into the air, offering breathtaking, panoramic views of Lake Michigan and the sprawling fairgrounds. At night, the wheel was illuminated by 3,000 incandescent light (9) bulbs, creating a brilliant, glowing halo visible from miles away.

⁵ Today, the Ferris wheel is a ubiquitous feature of amusement parks worldwide. While modern versions may be taller or feature high-tech observation cabins, they all owe their existence to Ferris's visionary design. (10)

Which of these choices makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. secured (correct answer)
  3. had secured
  4. securing

Explanation: The correct answer is B. The sentence establishes a parallel compound verb in the simple past: "He spent $25,000...and secured financial backing." "Has secured" is present perfect tense and breaks the parallelism with "spent." The narrative is set entirely in the historical past (1889-1893), so present perfect is contextually wrong as well. C ("had secured") is past perfect tense, implying that the act of securing funds came prior to spending his own money, but the logic of the action suggests that both events were simultaneous and should be parallel as the sentence demonstrates how he was able to pay for the venture. D ("securing") would create a dangling participle rather than a parallel verb. Pro tip: Parallelism questions often hinge on compound verbs joined by "and." Identify the tense of the first verb, then verify all subsequent verbs in the series match it.

Question 7

"The Comet Hunter\n\nBorn in Hanover in 1750, Caroline Herschel was not destined for scientific fame. Her mother viewed education as unnecessary for a girl, insisting that Caroline train only in household chores. In 1772, however, [10] Caroline's brother William rescued her from this limited life, bringing her to Bath, England, to join him. William was a musician with a growing passion for astronomy, and it wasn't long before Caroline begun [11] to share his enthusiasm.\n\nCaroline served as William's assistant, a role that required both physical stamina and intellectual precision. She ground and polished the metal mirrors for their telescopes, a task that often left her hands raw. William observed the heavens at the eyepiece, she sat [12] by a window, recording his data and double-checking his calculations. She worked diligently, [13] ensuring that every coordinate was accurate. It was during these long nights that she learned the geography of the night sky.\n\nEncouraged by William, Caroline began using a small Newtonian sweeper telescope to conduct her own observations. On August 1, 1786, she spotted a slow-moving object that wasn't on any star chart. It was a comet; the first [14] of eight she would discover over the next decade. Her success brought her international renown. In 1787, King George III granted her an annual salary of £50. This salary made [15] her the first woman in history to receive official payment for scientific work.\n\nCaroline's contributions extended beyond her comet discoveries. She compiled a massive catalogue of stars and nebulae, updating the work of the astronomer John Flamsteed. [16] This catalogue remained a standard reference for nearly half a century. If Caroline were [17] to see the advanced instruments used by astronomers today, she would marvel at their power, yet her meticulous methods would still be relevant. Caroline Herschel's life proved that curiosity and perseverance could break through the social barriers of the eighteenth century. [18]"

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. was beginning
  3. had began
  4. began (correct answer)

Explanation: This is a verb tense and grammar question testing irregular verb forms. You can tell because a verb form is underlined and the question asks which choice makes the sentence "most grammatically acceptable." The choices present different forms of the same verb, indicating you need to select the correct form for the context. For irregular verbs, memorize the three principal parts: present (begin), simple past (began), and past participle (begun). Use simple past for actions completed in the past with no helping verb. Use past participle only with helping verbs like "has," "have," or "had." The context (time frame, surrounding verbs, helping verbs) determines which form you need. Choice D (began) is correct because the sentence describes an action that happened and was completed in the past: "it wasn't long before Caroline began to share his enthusiasm." Simple past tense requires the form "began" with no helping verb. The surrounding verbs ("was," "brought") are also simple past, indicating the narrative is recounting past events. Choice A (NO CHANGE - "begun") is incorrect because "begun" is the past participle form, which requires a helping verb (has begun, had begun, have begun). Using "begun" alone is grammatically incorrect. Choice C ("had began") is incorrect because "had" requires the past participle "begun," not the simple past "began"—it should be "had begun" if past perfect were needed, but past perfect isn't appropriate here anyway since we're not describing an action completed before another past action. Choice B ("was beginning") is tempting because it's grammatically possible in isolation, but it creates awkward phrasing with "it wasn't long before." The idiom is "it wasn't long before X began" (completed action), not "before X was beginning" (ongoing action). Additionally, "was beginning" is unnecessarily verbose for the meaning. Remember: The ACT frequently tests irregular verb forms, especially begin/began/begun, lie/lay/lain, and rise/rose/risen. Memorize these forms! Pro tip: If you see "begun," "done," "gone," or "seen" alone without a helper verb, it's wrong. These past participles ALWAYS need "has," "have," or "had" in front of them.

Question 8

"Turn Right at the Big Pine\n\nMy father believed that road maps were for people who lacked a sense of adventure. He preferred to navigate by instinct, landmark, and the occasional contradictory tip from a gas station attendant. Consequently, [19] our annual family trips to the Cedar Creek campground were rarely straight lines; they were sprawling, improvisational loops through the backroads of Oregon.\n\nI was ten years old, sitting in the backseat of our station wagon, squeezed between a cooler full of soda and my sleeping brother. The air outside was thick with the scent of pine and dust. We had been driving for six hours, [20] but according to Dad, we were "just around the river bend." He pointed to a massive, gnarled tree standing sentinel at a fork in the road. "That's the Big Pine," he declared with the confidence of a ship captain spotting land. "We turn right here."\n\nWe turned right. The pavement immediately gave way to gravel, and the road narrowed until the blackberry bushes were scraping the sides of the car. My mother, who had been quietly reading a novel, looked up. "Honey," she said, her voice dropping an octave, "I don't think this is the way to the campsite." Dad waved a hand dismissively. He insisted that this was a shortcut he had discovered years ago. [21]\n\nTen minutes later, the road ended abruptly at a rusted gate marked "Private Property." A cow stared at us blankly from the other side. Silence filled the car. The cow chewed its cud, looking entirely unimpressed by our arrival. [22] Without a word, Dad shifted the car into reverse. As we backed down the dusty trail, he caught my eye in the rearview mirror and winked. "Well," he said, "now we know what's down that road." For him, the wrong turn wasn't a mistake; it was just another part of the story. [23]\n\n[1] We eventually found the campsite, arriving just as the sun was setting behind the mountains. [2] I realized then that the destination mattered less to him than the wandering it took to get there. [3] Years later, when I drive [25] my own kids on vacation, I keep a GPS on the dashboard. [4] But sometimes, when I see a strange road winding off into the trees I feel [24] a familiar tug to turn the wheel."

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE (correct answer)
  2. drove
  3. have driven
  4. was driving

Explanation: This is a verb tense question testing tense consistency within a time frame. You can tell because only the verb form is underlined and the question asks which choice makes the sentence "most grammatically acceptable." The choices present different tenses of the same verb, requiring you to match the correct tense to the time frame established in the passage. For verb tense questions, identify the time frame signals in the sentence and surrounding context. Words like "now," "today," "currently," "always" signal present tense. "Later," "in the past," "yesterday" signal past. "Years later" can signal either past or present depending on the narrative perspective. Look at other verbs in the same time frame to maintain consistency. Choice A (NO CHANGE - drive) is correct because the paragraph shifts from past tense narrative ("We eventually found the campsite") to the narrator's present-day reflection. "Years later" signals we've moved from the childhood story to the adult narrator's current life. The sentence continues "I keep a GPS on the dashboard"—"keep" is present tense, indicating habitual present action. "When I drive my own kids" maintains this present tense consistency, describing what the narrator does now, in the present. Choice B ("drove") would be past tense, suggesting a completed action, but "I keep a GPS" (present) makes clear we're in the narrator's present, not past. The tenses would clash: "when I drove... I keep" mixes time frames incorrectly. Choice C ("have driven") is present perfect, suggesting action that started in the past and continues or has present relevance. While not impossible, it's less natural here than simple present for habitual action. The sentence describes what happens regularly ("when I drive" = whenever I drive), not what has happened over a period. Choice D ("was driving") is past progressive, which would suggest an ongoing action in the past. But "I keep" (present) shows we're in the narrator's present life, not reminiscing about past driving. Remember: Verb tense consistency is crucial! When a paragraph shifts time frames (as narratives often do), pay close attention to tense signals. "Years later" often signals a shift from past narrative to present reflection. Pro tip: Look for a "tense anchor"—another verb in the same sentence or nearby that clearly establishes the time frame. In this case, "I keep a GPS" is your anchor showing you need present tense throughout this reflection section.

Question 9

PASSAGE III: The Architecture of Sleep

¹ Sleep is often viewed as a passive state, a time when the body shuts down to conserve energy. In reality, however, sleep is a highly active and complex biological process. While we rest, our brains are engaging in a neurological workout that is essential for physical health and mental clarity. This nightly maintenance is (23) governed by two opposing forces: the sleep drive, which builds up the longer we are awake, and the circadian rhythm, an internal "clock" that regulates our sleep-wake cycle based on light and darkness.

² Once asleep, the brain cycles through four distinct stages. The first three stages are known collectively as non-rapid eye movement (NREM) sleep. During the deepest part of NREM, (24) heart rate slows down, blood pressure drops, and the body repairs tissues. (25) Conversely, the fourth stage is rapid eye movement (REM) sleep. In this phase, brain activity spikes to levels similar to wakefulness. This is the stage where dreaming occurs and (26) memories were consolidated from short-term to long-term storage.

³ One of the most critical functions of sleep is "taking out the trash." For years, scientists wondered how the brain, (27) unlike other organs, cleared out metabolic waste products. In 2013, researchers discovered the "glymphatic system," a macroscopic waste clearance system formed by glial cells. During deep sleep, these cells shrink, increasing the space between neurons by up to 60 percent. This allows cerebrospinal fluid (28) to flow rapid through the brain tissue, flushing out toxic proteins associated with neurodegenerative diseases. (32)

⁴ (29) Neglecting this biological need has serious consequences. Sleep deprivation impairs cognitive function, weakens the immune system, and increases the risk of chronic conditions like heart disease. (30) Experts recommend adults get between seven and nine hours of sleep per night. Despite these risks, modern society often treats sleep as a luxury rather than a necessity. Artificial lighting and digital screens (31) disrupts the production of melatonin, the hormone that signals to the body that it is time to rest.

⁵ We cannot cheat our biology. Caffeine and sheer willpower can only mask the symptoms of fatigue for so long. Eventually, the "sleep debt" must be repaid. By prioritizing sleep, we are not being lazy; we are investing in our long-term health. The architecture of sleep is built on a foundation of millions of years of evolution, and (33) it remains the most effective medicine we have. (34)

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. memories are consolidated (correct answer)
  3. memories had been consolidated
  4. memories being consolidated

Explanation: This is a verb tense question. Choice B (are consolidated) is correct—uses present tense to match the passage's general, timeless explanations ("occurs," "spikes"). Choice A (were consolidated) incorrectly uses past tense. Choice C (had been) uses past perfect unnecessarily. Choice D (being consolidated) creates a fragment. Pro tip: Match verb tense to the passage's established timeline.

Question 10

PASSAGE IV: The Accidental Toy

¹ Many of the world's most popular inventions were created by accident. In 1943, a naval engineer named Richard James (31) is trying to invent a set of tension springs that could keep sensitive ship equipment steady at sea. During a test in his laboratory, he accidentally knocked one of the coiled springs off a shelf. Instead of simply crashing to the floor, the steel spring "stepped" in a series of arcs from a stack of books, to a tabletop, and finally down to the ground, where it neatly coiled itself back up.

² James was mesmerized by the fluid, walking motion of the metal. He immediately realized the spring had potential as a novelty item. (39) After calculating the exact amount of tension required to make the spring walk smoothly, he spent the next year perfecting the formula. His wife, (32) Betty named the toy the "Slinky" after finding the word in a dictionary; she felt the word perfectly described the graceful, sinuous movement of the spring.

³ In 1945, Richard and Betty James manufactured the first batch of four hundred Slinkys. They convinced the manager of Gimbels Department Store (33) in Philadelphia, Pennsylvania, to allow them to set up a display during the Christmas shopping season. (38) Initially, the toys sat unsold for days. However, once Richard set up an inclined board and demonstrated how the metal spring could walk down the ramp on its own, a crowd quickly gathered. Within ninety minutes, all four hundred Slinkys had been sold.

⁴ The Slinky became a massive success, but its simple design presented a unique manufacturing challenge. To keep the cost low, the factory had to cut and coil the steel wire with absolute precision. (34) Because each of the springs needed to have exactly ninety-eight coils. If the tension was even slightly off, the Slinky would not walk.

⁵ Despite these challenges, the James family eventually expanded their production to include plastic versions of the toy. The plastic models could be dyed in bright, vibrant colors, making them even more appealing to young children. (35) Meanwhile, the Slinky remains one of the best-selling toys in American history. Over 300 million units have been sold worldwide. The incredible popularity of this simple coil of wire proves that (36) a toy that is fun and enjoyable to play with doesn't need batteries or microchips to capture the imagination. (37)

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. was trying (correct answer)
  3. has tried
  4. tries

Explanation: The correct answer is B. The entire narrative is set in the historical past, established immediately by "In 1943." The past progressive tense "was trying" correctly describes an ongoing action in progress at a specific past moment — Ferris was in the process of inventing the springs when the accident occurred. A ("is trying") is present tense, inconsistent with the historical narrative. C ("has tried") is present perfect, which implies an action connected to the present rather than firmly anchored in 1943. D ("tries") is simple present tense, also inconsistent with the past-tense narrative. Pro tip: When a sentence opens with a specific historical date ("In 1943"), that is your anchor for verb tense. All verbs in the paragraph describing events at that time must use past tense.

Question 11

PASSAGE V: The Yellowstone Effect

¹ For nearly seventy years, the gray wolf was completely absent from Yellowstone National Park. Hunted to local extinction in the 1920s, the predator's removal triggered a cascade of negative ecological consequences. Without wolves to keep them in check, the park's elk population exploded. (41) Elk which had overpopulated the park grazed heavily on young willow and aspen trees. As the trees disappeared, so did the songbirds and beavers that relied on them for habitat. By the late twentieth century, Yellowstone's ecosystem was severely unbalanced. (49)

² In 1995, wildlife biologists initiated a controversial program to reintroduce the gray wolf to the park. The scientists predicted that the wolves would cull the elk herds, but what happened next surprised even the most optimistic ecologists. The wolves triggered a phenomenon known as a "trophic cascade," where an apex predator's presence creates a ripple effect throughout the entire food web. (42)

³ The wolves began hunting the elk, which significantly reduced the grazing pressure on the valleys and gorges. (43) Growing along the riverbanks, the elk avoided the open areas where they were most vulnerable. Because the elk were constantly on the move, the young willow and aspen saplings finally had a chance to mature.

⁴ As the forests (44) had recovered, the ecosystem began to transform. The renewed tree growth provided ample wood for beavers, whose population rapidly increased. The beavers built dams, creating deep, cold pools of water that provided ideal habitats for fish, otters, and muskrats. Furthermore, the carcasses of elk hunted by wolves provided a reliable food source for scavengers, including ravens, bald eagles, and grizzly bears. (45) As a result of the consequence of this, the entire biodiversity of the park stabilized.

⁵ Perhaps the most astonishing consequence of (46) the wolfs return was the alteration of Yellowstone's physical geography. Because the stabilizing vegetation prevented soil erosion, the park's rivers actually changed course, becoming deeper and more fixed in their channels. The intricate web of predator and prey relationships (47) are fascinating, proving that sometimes, introducing a fearsome predator is the only way to heal a broken landscape. (48)

Which of these answer choices makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. recovered, (correct answer)
  3. have recovered,
  4. were recovering,

Explanation: The correct answer is B. The sentence reads "As the forests recovered, the ecosystem began to transform." Both actions — the forests recovering and the ecosystem transforming — are occurring in the same general timeframe as part of the ongoing cascade of changes in Yellowstone. Simple past "recovered" correctly places both events on the same temporal plane. A ("had recovered") is past perfect, which signals that one action was fully completed before another began — but the passage presents the forest recovery and ecosystem transformation as simultaneous and interconnected processes, not sequential ones. Using past perfect implies the forests finished recovering and only then did the ecosystem begin to change, which misrepresents the passage's description of a continuous, overlapping cascade. C ("have recovered") is present perfect, which implies the forests' recovery is connected to the present moment — inconsistent with the past-tense narrative throughout the passage. D ("were recovering") is past progressive, which implies an ongoing, incomplete action — but the sentence is describing a condition that enabled the ecosystem transformation, requiring a completed simple past rather than a progressive form. Pro tip: Past perfect ("had + past participle") is only correct when one past action was definitively completed before a second past action began. When two past events happen simultaneously or are intertwined, simple past is always the right choice.

Question 12

PASSAGE I: The Invisible Art of Noise

¹ When watching a movie, audiences usually focus on the actors' dialogue or the sweeping musical score. Rarely do they consider the crunch of footsteps in snow, the rustle of a silk dress, or the squeak of a saddle. Most viewers assume these sounds were recorded on set during filming. In reality, however, microphones are designed to pick up dialogue, not background noise. Most of the detailed sounds you hear (1) has been created weeks later in a studio by a specialized craftsperson known as a Foley artist.

² Named after Jack Foley, a sound editor at Universal Studios in the 1920s, the profession requires a unique blend of creativity and athleticism. Foley artists work on specialized stages containing recessed areas called "Foley pits." These pits hold different surfaces—gravel, dirt, hardwood, and more—that mimic real-world textures. To recreate the sound of a character walking, the artist watches the screen and mimics the actor's steps, (2) wearing the shoes that match the character's footwear. If the character is walking on broken glass, the artist steps on scattered ceramic tiles. (3) Having carefully selected the proper materials, the realistic sound is created.

³ The work involves more than just footsteps. Foley artists must be inventive to (4) generate sounds that do not exist in the real world. For a science fiction film, the sound of an alien egg hatching (5) might be created by squishing a honeydew melon. (6) On the other hand, the bone-crunching impact of a fistfight is often simulated by breaking stalks of celery or snapping carrots wrapped in a towel. The goal is realistic audio, even if the source is decidedly artificial.

⁴ Precision is critical. The sound must sync perfectly with the visual action. If a sword is drawn from a sheath one second too late, the illusion is shattered. Foley artists often perform "wild tracks," recording sounds without watching the picture, (7) but for complex scenes, they must perform in real-time, matching their movements to the actor's rhythm.

⁵ Despite their importance, Foley artists often go unrecognized. Their work is successful only when it goes unnoticed. If the audience realizes the sound of a horse's hooves is actually (8) two halves of a coconut shell being banged together, the magic is lost. Like a magician's trick, the art of Foley relies on misdirection.

⁶ Today, digital libraries offer thousands of pre-recorded sound effects. Many directors still prefer the custom touch of a human artist. A canned sound effect is static and repetitive, (9) whereas a Foley performance is organic. It breathes life into the visual image, giving weight and texture to the world on screen. (10) The next time you watch an old horror movie, remember that someone might be standing in a studio, slowly twisting an old rusty hinge.(11)

Which of the following choices makes the sentence most grammatically acceptable?

  1. NO CHANGE (correct answer)
  2. might of been created
  3. could of been created
  4. might be creating

Explanation: This is a verb form question testing the common "might of" error. Choice A (NO CHANGE: might be created) is correct because it uses the proper modal + passive infinitive construction. Passive voice is appropriate since the focus is on the sound being created, not who creates it. Choices B and C contain the extremely common error of using "of" instead of "have." This error comes from mishearing "might've" or "could've" in speech. "Of" is a preposition and cannot function as part of a verb phrase. Choice D (might be creating) uses active voice incorrectly—the sound doesn't create itself. Pro tip: If you see "of" after modals like "might," "could," or "would," it's almost always wrong—should be "have."

Question 13

PASSAGE III: The Architecture of Sleep

¹ Sleep is often viewed as a passive state, a time when the body shuts down to conserve energy. In reality, however, sleep is a highly active and complex biological process. While we rest, our brains are engaging in a neurological workout that is essential for physical health and mental clarity. This nightly maintenance is (23) governed by two opposing forces: the sleep drive, which builds up the longer we are awake, and the circadian rhythm, an internal "clock" that regulates our sleep-wake cycle based on light and darkness.

² Once asleep, the brain cycles through four distinct stages. The first three stages are known collectively as non-rapid eye movement (NREM) sleep. During the deepest part of NREM, (24) heart rate slows down, blood pressure drops, and the body repairs tissues. (25) Conversely, the fourth stage is rapid eye movement (REM) sleep. In this phase, brain activity spikes to levels similar to wakefulness. This is the stage where dreaming occurs and (26) memories were consolidated from short-term to long-term storage.

³ One of the most critical functions of sleep is "taking out the trash." For years, scientists wondered how the brain, (27) unlike other organs, cleared out metabolic waste products. In 2013, researchers discovered the "glymphatic system," a macroscopic waste clearance system formed by glial cells. During deep sleep, these cells shrink, increasing the space between neurons by up to 60 percent. This allows cerebrospinal fluid (28) to flow rapid through the brain tissue, flushing out toxic proteins associated with neurodegenerative diseases. (32)

⁴ (29) Neglecting this biological need has serious consequences. Sleep deprivation impairs cognitive function, weakens the immune system, and increases the risk of chronic conditions like heart disease. (30) Experts recommend adults get between seven and nine hours of sleep per night. Despite these risks, modern society often treats sleep as a luxury rather than a necessity. Artificial lighting and digital screens (31) disrupts the production of melatonin, the hormone that signals to the body that it is time to rest.

⁵ We cannot cheat our biology. Caffeine and sheer willpower can only mask the symptoms of fatigue for so long. Eventually, the "sleep debt" must be repaid. By prioritizing sleep, we are not being lazy; we are investing in our long-term health. The architecture of sleep is built on a foundation of millions of years of evolution, and (33) it remains the most effective medicine we have. (34)

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. memories are consolidated (correct answer)
  3. memories had been consolidated
  4. memories being consolidated

Explanation: This is a verb tense question. Choice B (are consolidated) is correct—uses present tense to match the passage's general, timeless explanations ("occurs," "spikes"). Choice A (were consolidated) incorrectly uses past tense. Choice C (had been) uses past perfect unnecessarily. Choice D (being consolidated) creates a fragment. Pro tip: Match verb tense to the passage's established timeline.

Question 14

If the weather clears by Saturday, our hiking club will take the trail along the river. The forecast says it might rain, so we are packing ponchos just in case. We also agreed to leave early to avoid the afternoon heat. If it rained, we would switch to an indoor climbing gym instead.

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. rains (correct answer)
  3. had rained
  4. will rain

Explanation: This question tests conditional verb forms in hypothetical situations. The sentence presents a conditional statement about weather alternatives, where 'if it rained' sets up a hypothetical condition. Simple present 'rains' is correct for the conditional clause, following standard English conditional patterns. Past tense, past perfect, and future tense create awkward or incorrect conditional constructions. In conditional statements, use simple present in the 'if' clause when describing possible future scenarios, even though the main clause uses conditional 'would.'

Question 15

After she had finished her homework, she went out to play.

  1. NO CHANGE (correct answer)
  2. finishes
  3. finished
  4. was finishing

Explanation: This question tests the distinction between past perfect and other past tenses in temporal sequences. The word 'After' indicates that one past action was completed before another past action occurred. Past perfect 'had finished' correctly shows that the homework completion occurred before she went out to play. The other options don't establish this temporal relationship: 'finishes' is present, 'finished' is simple past without the sequence, and 'was finishing' is past continuous. Use past perfect (had + past participle) when one past action was completed before another past action occurred.

Question 16

"The Comet Hunter\n\nBorn in Hanover in 1750, Caroline Herschel was not destined for scientific fame. Her mother viewed education as unnecessary for a girl, insisting that Caroline train only in household chores. In 1772, however, [10] Caroline's brother William rescued her from this limited life, bringing her to Bath, England, to join him. William was a musician with a growing passion for astronomy, and it wasn't long before Caroline begun [11] to share his enthusiasm.\n\nCaroline served as William's assistant, a role that required both physical stamina and intellectual precision. She ground and polished the metal mirrors for their telescopes, a task that often left her hands raw. William observed the heavens at the eyepiece, she sat [12] by a window, recording his data and double-checking his calculations. She worked diligently, [13] ensuring that every coordinate was accurate. It was during these long nights that she learned the geography of the night sky.\n\nEncouraged by William, Caroline began using a small Newtonian sweeper telescope to conduct her own observations. On August 1, 1786, she spotted a slow-moving object that wasn't on any star chart. It was a comet; the first [14] of eight she would discover over the next decade. Her success brought her international renown. In 1787, King George III granted her an annual salary of £50. This salary made [15] her the first woman in history to receive official payment for scientific work.\n\nCaroline's contributions extended beyond her comet discoveries. She compiled a massive catalogue of stars and nebulae, updating the work of the astronomer John Flamsteed. [16] This catalogue remained a standard reference for nearly half a century. If Caroline were [17] to see the advanced instruments used by astronomers today, she would marvel at their power, yet her meticulous methods would still be relevant. Caroline Herschel's life proved that curiosity and perseverance could break through the social barriers of the eighteenth century. [18]"

Which of these choices makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. was
  3. would be (correct answer)
  4. could be

Explanation: This is a verb tense question testing the subjunctive mood. You can tell because the underlined verb appears in a hypothetical "if" statement and the question asks which choice makes the sentence "most grammatically acceptable." The choices present different verb forms, indicating you must select the grammatically correct form for hypothetical/contrary-to-fact conditions. The subjunctive mood is used for hypothetical, contrary-to-fact, or wish situations. The key signal is "if" followed by a condition that isn't real or factual. The subjunctive form is "were" (not "was") for all subjects in these hypotheticals: "If I were rich," "If she were here," "If it were possible." For present-contrary-to-fact hypotheticals, use "If [subject] were to [verb]" or "If [subject] were [adjective/noun]." Choice C (NO CHANGE - were) is correct because this is a contrary-to-fact hypothetical—Caroline Herschel is dead, so she cannot actually see modern instruments. For hypothetical conditions like this, English uses the subjunctive mood: "If Caroline were to see" (not "was"). This is one of the few remaining uses of the subjunctive in English, and it's grammatically required for hypotheticals. Choice B ("was") is incorrect despite sounding natural to many speakers. "If Caroline was" is commonly used in casual speech, but in formal written English (which the ACT tests), hypotheticals require "were" regardless of whether the subject is singular or plural. This is the subjunctive mood. Choice C ("would be") is incorrect because you use "would" in the result clause ("she would marvel"), not in the "if" clause itself. The pattern is "If [subject] were to [verb], [subject] would [verb]." Choice D ("could be") is also incorrect because modal verbs like "could" don't work with "to see" in this construction—you'd need "could see" without the "to," but even then, "were to see" is the correct subjunctive form. The ACT loves to test the subjunctive mood because many students don't recognize it in formal writing! This is an elite-level grammar concept. Pro tip: Whenever you see "If" followed by a hypothetical situation (especially about someone deceased, or an impossible scenario), look for "were" as the answer, even with singular subjects. The subjunctive "were" is always correct for contrary-to-fact conditionals, and "was" is always wrong in formal English, even though it sounds okay in speech. Memorize this: "If I were you," "If she were here," "If it were possible"—always "were" for hypotheticals!

Question 17

Tonight, our class is hosting a fundraiser dinner, and we expect a large crowd. Right now, volunteers are arranging chairs, and the kitchen staff is preparing trays of food. The organizer promised that if more guests arrive than expected, we served extra portions without running out because a nearby restaurant offered to help.

  1. NO CHANGE
  2. will serve extra portions without running out (correct answer)
  3. have served extra portions without running out
  4. had served extra portions without running out

Explanation: This question tests future tense in a conditional promise about tonight's event. The context establishes present preparations ("Tonight," "Right now") and a future condition ("if more guests arrive"). The correct answer is B ("will serve extra portions") because future tense correctly expresses what will happen if the condition is met. Choice A incorrectly uses past tense ("served") for a future action. When describing future plans or promises, especially with "if" conditions, use will + base verb.

Question 18

In the interview, the scientist explained that her team studies how bees communicate. She said that, before the researchers installed cameras inside the hive, they relied mostly on brief outdoor observations. Once the cameras were in place, the team records hundreds of hours of footage and discovered patterns they had missed.

  1. NO CHANGE
  2. recorded hundreds of hours of footage (correct answer)
  3. has recorded hundreds of hours of footage
  4. will record hundreds of hours of footage

Explanation: This question tests simple past tense in reported speech about completed research. The scientist is describing what happened after cameras were installed: first installation, then recording, then discovery. The correct answer is B ("recorded hundreds of hours") because simple past maintains the sequence of completed actions in the past. Choice A incorrectly uses present tense ("records") for a past event. In reported speech about past events, maintain past tense consistency unless there's a reason to shift.

Question 19

During last Saturday's neighborhood cleanup, volunteers worked in small teams to collect litter along the creek. By noon, the group had filled dozens of bags, and the organizers announced that a local bakery would donate snacks. When the final tally was posted that evening, everyone was surprised by how much they had accomplished in just a few hours. One volunteer wrote in the shared log that she brings extra gloves because several people forgot theirs.

Which choice makes the sentence most grammatically acceptable?

  1. NO CHANGE
  2. she brought extra gloves because several people forgot theirs (correct answer)
  3. she has brought extra gloves because several people have forgotten theirs
  4. she will bring extra gloves because several people forgot theirs

Explanation: This question tests the ability to maintain consistent past tense throughout a narrative. The entire passage describes events from 'last Saturday,' establishing a past time frame with verbs like 'worked,' 'had filled,' 'announced,' and 'was surprised.' The correct answer (B) 'she brought extra gloves because several people forgot theirs' uses simple past tense to match the established timeframe. Choice A incorrectly uses present tense 'brings,' which clashes with the past context. Choice C uses present perfect 'has brought' and 'have forgotten,' suggesting ongoing relevance that doesn't fit a completed past event. When describing completed past events, maintain simple past tense unless the context specifically indicates a different time relationship.

Question 20

By the time you read this, I will have left for the airport.

  1. NO CHANGE (correct answer)
  2. left
  3. leave
  4. was leaving

Explanation: This question tests the distinction between future perfect and other future constructions. The phrase 'By the time you read this' establishes a future point when another action will have been completed. Future perfect 'will have left' correctly expresses an action that will be completed before the reading occurs. The other options don't capture this temporal relationship: 'left' is past tense, 'leave' is present/base form, and 'was leaving' is past continuous. Use future perfect (will have + past participle) for actions that will be completed before a specific future event occurs.