Author's
Purpose

Master the skill of identifying why an author writes: to inform, persuade, entertain, or express. A critical skill for the ACT Reading section.

ACT Reading

What Is Author's Purpose?

Every passage on the ACT was written for a reason. Author's purpose is the underlying intention behind a text: the goal the writer had in mind when choosing their words, structure, and tone.

The Four Core Purposes

Inform

Present facts, data, or explanations to educate the reader about a topic.

Persuade

Convince the reader to adopt a viewpoint or take an action using arguments.

Entertain

Engage the reader through narrative, humor, imagery, or dramatic tension.

Express

Share personal feelings, reflections, or experiences with the reader.

Why It Matters on the ACT

The ACT Reading section tests author's purpose both directly and indirectly. You will see questions about the purpose of entire passages, individual paragraphs, specific sentences, and even single word choices.

1

Passage-level: "The primary purpose of this passage is to..."

2

Paragraph-level: "The third paragraph primarily serves to..."

3

Detail-level: "The author includes the statistic in line 24 in order to..."

The Purpose Framework

Purpose vs. Main Idea

	Author's Purpose	Main Idea
Question	Why did the author write this?	What is the author saying?
Focus	The author's goal	The passage's content
Answer type	Verb-driven: to argue, to explain, to illustrate	Noun-driven: the effects of, the history of
Example	"to challenge a common assumption"	"urban wildlife adapts to human activity"

Recognizing Purpose: Signal Words

Inform

"according to," "research shows," "studies indicate," "the data reveal"

Persuade

"must," "should," "it is essential," "one cannot deny," "clearly"

Entertain

Vivid imagery, dialogue, suspense, figurative language, humor

Express

"I remember," "it felt like," "looking back," first-person reflection

The 4-Step Strategy

1

Read the question carefully. Determine whether it asks about the whole passage, a paragraph, or a specific detail.

2

Identify the scope. Re-read the relevant section. Note the tone, word choice, and structure.

3

Ask "Why?" Before looking at choices, form your own answer: "The author wrote this in order to..."

4

Match and eliminate. Pick the choice closest to your prediction. Eliminate answers that describe what is said, not why.

Example 1: Informational Passage

Question: The primary purpose of this passage is to...

✓ Correct

"...explain scientific findings about monarch butterfly navigation."

✕ Trap

"...argue that monarchs are more intelligent than previously thought."

Example 2: Persuasive Passage

Question: The author's purpose in this paragraph is most likely to...

✓ Correct

"...advocate for continued funding of public libraries."

✕ Trap

"...describe the history of public libraries in America."

Example 3: Detail-Level Purpose

Question: The author most likely includes the survey statistic in order to...

1

Identify the claim being supported or undermined. The mayor's praise is the claim.

2

Ask what the detail does. The 23% statistic undercuts the mayor's optimism.

3

Best answer: "to cast doubt on the viability of the proposed transit plan."

ACT Passage Types and Typical Purposes

Passage Type	Common Purpose	Look For
Literary Narrative	Entertain / Express	Imagery, character arc, reflection
Social Science	Inform / Analyze	Studies cited, neutral tone, data
Humanities	Inform / Express	Personal essay, cultural analysis
Natural Science	Inform / Explain	Processes, findings, terminology

Purpose at Different Levels

Common Purpose Verbs

Informing

describe, explain, illustrate, clarify, define, compare, trace, outline

Persuading

argue, advocate, challenge, defend, criticize, refute, urge, promote

Supporting

support, reinforce, provide evidence, demonstrate, justify, substantiate

Qualifying

concede, acknowledge, qualify, complicate, undermine, cast doubt on

Common Mistakes to Avoid

✕ Confusing Purpose with Topic

The topic is what the passage is about. The purpose is why the author wrote about it. "Climate change" is a topic; "to argue for policy reform" is a purpose.

✕ Choosing Too Broad an Answer

"To inform the reader" is almost always too vague. The correct answer will specify what is being informed or explained.

✕ Ignoring Tone Mismatch

If the passage is neutral and objective, an answer like "to criticize" or "to celebrate" is wrong, even if the topic matches.

Question 1 of 5

"The Amazon rainforest plays a critical role in regulating global climate, storing billions of tons of carbon. It also houses an estimated 10% of all known species on Earth. Deforestation rates have accelerated in recent decades, driven by agricultural expansion and logging. According to satellite data from Brazil's National Institute for Space Research, the rate of forest loss increased significantly between 2018 and 2020."

▼ Tap to read passage

The primary purpose of this passage is to:

The passage uses neutral, data-driven language ("according to satellite data," "an estimated 10%"). There is no opinion, argument, or emotional language. The purpose is to inform.

Question 2 of 5

"No serious observer can deny that our public education system is failing the very students it was designed to serve. Graduation rates in urban districts lag 15 points behind national averages, and standardized test scores continue their downward slide. It is time for bold, structural reform: school choice, performance-based teacher pay, and community-driven accountability."

▼ Tap to read passage

Which of the following best describes the author's purpose?

The phrases "no serious observer can deny," "it is time for," and the list of specific proposals are hallmarks of persuasive writing. The author is advocating for action.

Question 3 of 5

A passage about jazz music states: "Miles Davis's 1959 album Kind of Blue sold over 5 million copies and is widely regarded as the greatest jazz recording ever made." The author most likely includes this detail in order to:

The detail uses objective evidence (sales figures, critical reputation) to support a larger point about Davis's importance. The purpose is to illustrate significance, not to sell or reminisce.

Question 4 of 5

"I remember the summer my grandfather taught me to fish. The lake was glass-still at dawn, and the air smelled of pine and wet earth. He never said much, but the silence between us held more meaning than any conversation I've had since. That summer, I learned that presence is its own kind of language."

▼ Tap to read passage

The author's primary purpose in this paragraph is to:

First-person narration, sensory imagery ("glass-still," "smelled of pine"), and emotional reflection ("more meaning than any conversation") signal expressive/reflective writing. The purpose is to share a personal experience and its emotional significance.

Question 5 of 5

An author writes a paragraph about renewable energy that begins with a concession: "Critics are right that wind turbines can harm bird populations." She then provides data showing that fossil fuel plants kill 15 times more birds per unit of energy produced. The author includes the concession most likely to:

A concession followed by a rebuttal is a classic persuasive technique. By acknowledging the opposing view first, the author appears fair-minded, which makes her counter-evidence more convincing. This strengthens her overall argument.

Author'sPurpose

What Is Author's Purpose?

The Four Core Purposes

Why It Matters on the ACT

The Purpose Framework

Purpose vs. Main Idea

Recognizing Purpose: Signal Words

The 4-Step Strategy

Example 1: Informational Passage

Example 2: Persuasive Passage

Example 3: Detail-Level Purpose

ACT Passage Types and Typical Purposes

Purpose at Different Levels

Common Purpose Verbs

Common Mistakes to Avoid

Question 1 of 5

Question 2 of 5

Question 3 of 5

Question 4 of 5

Question 5 of 5

Author's
Purpose