Parallel Structure — Revise a list so items are parallel in...

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Why Parallel Structure Matters

Have you ever read a sentence that just felt "off" even though you couldn't explain why? Chances are, the writer broke a rule called parallel structure. This rule says that when you list things in a sentence, every item should follow the same grammatical pattern. Writers and speakers have cared about this idea for thousands of years.

~350 BC

Aristotle's Rhetoric

The Greek philosopher Aristotle taught students that balanced sentences are easier to follow and more persuasive. He called this idea parisosis — equal structure.

1776

The Declaration of Independence

Thomas Jefferson used parallel structure throughout the Declaration: "Life, Liberty, and the pursuit of Happiness." Each item is a noun or noun phrase, creating a powerful rhythm.

1963

"I Have a Dream" Speech

Dr. Martin Luther King Jr. repeated parallel phrases like "I have a dream that one day…" to create one of the most memorable speeches in history.

Today

Standardized Tests (SHSAT)

The SHSAT Revising and Editing section tests whether you can spot and fix faulty parallelism in lists, comparisons, and paired ideas.

So here's the big question: how do you know when a list is not parallel, and how do you fix it? That's exactly what this lesson will teach you.

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Core Principles of Parallel Structure

Parallel structure (also called parallelism) means that items joined by a conjunction (words like and, or, but) or listed in a series must share the same grammatical form. If the first item is a verb, every item should be a verb. If the first item is a noun, every item should be a noun.

Match the Part of Speech

Every item in a list should be the same part of speech — all nouns, all verbs, all adjectives, etc.

Match the Verb Form

If one item uses an -ing verb (gerund), all items should use -ing verbs. If one uses to + verb (infinitive), all should.

Match the Phrase Type

If one item is a full clause (subject + verb), then all items should be full clauses. Don't mix clauses with single words.

Check After Correlative Pairs

Word pairs like either…or, both…and, and not only…but also require matching structure on both sides.

✦ KEY TAKEAWAY

Think of parallel structure like a matching outfit. If you're wearing a striped shirt, striped pants, and a polka-dot hat, something looks wrong. In the same way, if two items in your list are -ing verbs and the third is a noun, the sentence feels unbalanced. Make every item "wear" the same pattern!

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Seeing Parallel vs. Non-Parallel Structure

The diagram below shows two versions of the same sentence. On the left, the items in the list don't match — one is a gerund (-ing word), one is an infinitive (to + verb), and one is a plain noun. On the right, every item uses the same form, making the sentence balanced and clear.

On the left, the three items use three different forms: a gerund, an infinitive, and a noun phrase. On the right, all three items are gerunds (-ing words), making the list parallel.

Notice how each item on the right side is the same kind of word. That's the secret: pick one form and stick with it across every item in the list.

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How Parallel Structure Works in Sentences

Let's dig deeper into the mechanics. Parallel structure shows up in three main places inside a sentence: lists of words, lists of phrases, and lists of clauses.

Words in a List

When you list single words, make sure they're all the same part of speech. For example: "The dog is loyal, friendly, and playful." All three words are adjectives. If you wrote "loyal, friendly, and likes to play," you'd break the pattern.

Phrases in a List

A phrase (a group of words without its own subject and verb) must match other phrases in the list. For example: "He spends his weekends reading books, playing video games, and walking his dog." Each phrase starts with an -ing verb.

Clauses in a List

A clause (a group of words that has its own subject and verb) should match other clauses. For example: "The teacher explained what we should study, how we should prepare, and when we should arrive." Each clause follows the same pattern: question word + we should + verb.

💡 SHSAT Tip

On the SHSAT, the question often gives you a sentence with a list where one item doesn't match the others. Your job is to pick the answer choice that makes the odd item match. Look at the items you can't change first — they tell you which form to follow.

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Common Parallelism Errors and How to Fix Them

Knowing the rule is one thing. Spotting mistakes in real sentences is another. Let's look at the most common parallelism errors you'll see on the SHSAT and learn how to fix each one.

Follow this flowchart every time you check a list for parallelism. First, find the list. Then label each item's form. If they don't match, rewrite the odd item to match the majority.

Common parallelism errors and their corrected versions

Error Type	Non-Parallel Example	Parallel Revision
Mixed verb forms	She likes running, to swim, and biking.	She likes running, swimming, and biking.
Noun vs. clause	The recipe calls for flour, sugar, and you need eggs.	The recipe calls for flour, sugar, and eggs.
Adjective vs. phrase	The park is quiet, beautiful, and has a lot of space.	The park is quiet, beautiful, and spacious.
Correlative pair mismatch	She not only sings but also is a dancer.	She not only sings but also dances.

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Worked Example: Fixing a Faulty List

Let's walk through a full example, the same way you'd tackle it on the SHSAT.

Revise for Parallel Structure

Step 1 — Read the sentence and find the listOriginal sentence: "To prepare for the science fair, Marcus spent time researching his topic, to build his display board, and practicing his presentation." The list has three items joined by commas and the word "and."

Step 2 — Label the grammar form of each itemItem 1: "researching his topic" → gerund phrase (-ing). Item 2: "to build his display board" → infinitive phrase (to + verb). Item 3: "practicing his presentation" → gerund phrase (-ing). Two out of three items use the gerund form.

Mismatch found: Item 2 is an infinitive, but Items 1 and 3 are gerunds.

Step 3 — Pick the dominant formSince two items already use -ing (gerund) form, the best fix is to change Item 2 to match. The majority wins!

Step 4 — Rewrite the odd itemChange "to build his display board" to "building his display board." This keeps the same meaning but now uses the gerund form.

Revised sentence: "To prepare for the science fair, Marcus spent time researching his topic, building his display board, and practicing his presentation."

Step 5 — Double-checkRead the revised sentence aloud. All three items — researching, building, practicing — are -ing words. The list sounds smooth and balanced. Done!

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Tricky Situations and Pitfalls

Some parallelism problems are easy to spot. Others are sneaky. Let's look at situations where students often go wrong.

Tricky parallelism situations and strategies

Tricky Situation	Why It's Hard	What to Do
Long sentences	When a sentence is long, the list items are far apart. You might not notice they don't match.	Underline or number each list item. Compare them side by side.
Hidden lists	Some lists don't use commas. They use "and" or "or" to join just two items.	Even a two-item pair ("likes reading and to write") needs to be parallel.
Correlative conjunctions	"Either…or," "not only…but also" look fancy. Students forget that whatever follows each half must match.	Cover everything before the first word of the pair. The structures after each word must be identical in form.
Multiple correct fixes	You could make all items nouns OR all items gerunds — both are parallel. On the SHSAT, only one answer choice will be offered.	Don't panic. Read each answer choice and check if it creates a fully parallel list.

✦ KEY TAKEAWAY

Think of parallelism like a relay race. Each runner hands the baton in the same smooth motion. If one runner suddenly decides to throw the baton instead of handing it, the whole team stumbles. In a sentence, each list item is a "runner." They all need to move the same way — same grammar form — for the sentence to flow.

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Parallel Structure Beyond Simple Lists

On the SHSAT, most parallelism questions focus on lists. But as you move into high school, you'll see parallelism used in bigger ways. Here's a quick peek at where this skill goes next.

Parallelism skills: SHSAT level vs. advanced level

SHSAT Level (Lists)	High School Level (Advanced)
Fix a 3-item list so all items match	Balance entire paragraphs with parallel topic sentences
Fix "either…or" pairs	Use parallelism for rhetorical effect in persuasive essays
Identify gerund vs. infinitive mismatches	Maintain parallelism across compound-complex sentences
Choose the best revision from answer choices	Write original parallel sentences for style and emphasis

Mastering parallel structure now gives you a strong foundation. Once you can fix a list, you can use parallelism on purpose to make your own writing powerful and persuasive — just like Aristotle, Jefferson, and Dr. King did.

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Practice Problems

Try these five problems on your own. For each one, identify the parallelism error and choose or write the best revision. Then check the answer.

PROBLEM 1 — CONCEPTUAL

Which sentence uses parallel structure correctly? A) The students were told to study hard, take good notes, and that they should ask questions. B) The students were told to study hard, take good notes, and ask questions. C) The students were told studying hard, to take good notes, and asking questions. D) The students were told to study hard, taking good notes, and questions they should ask.

PROBLEM 2 — BASIC

Revise the following sentence so the list is parallel: "On weekends, Priya enjoys painting, to read mystery novels, and she sometimes bakes cookies."

PROBLEM 3 — INTERMEDIATE

Which revision of the underlined portion makes the sentence parallel? "The coach told the team to warm up, stretch their muscles, and that they should run two laps." A) running two laps B) to be running two laps C) run two laps D) they need to run two laps

PROBLEM 4 — APPLIED

Read this passage from a student essay and fix the parallelism error: "Volunteering at the food bank taught me three important things: how to work with a team, being responsible for tasks, and the importance of giving back to the community."

PROBLEM 5 — CRITICAL THINKING

A student argues that this sentence is already parallel: "The mayor promised not only to lower taxes but also creating more jobs." The student says both items describe things the mayor will do, so they match. Explain why the student is wrong and provide a corrected version.

SUMMARY

Parallel Structure — Quick Review

Parallel structure means every item in a list must share the same grammatical form. If the first item is a gerund (-ing word), every item should be a gerund. If it's an infinitive (to + verb), every item should be an infinitive. This rule applies to lists of words, phrases, and clauses.

To fix a non-parallel list, follow these steps: find the list, label each item's form, identify the odd item, and rewrite it to match the others. Watch for tricky spots like correlative conjunctions (either…or, not only…but also), where the structure after each word in the pair must match. On the SHSAT, look at the items you can't change to figure out which form the answer should follow.