TACHS Reading • Reading Comprehension

Determine the author's purpose

Learn to figure out why an author wrote a passage so you can understand it on a deeper level.

TACHS illustration with a Catholic high school, reading book, and math calculator
Inside this lesson 10 sections 5 questions 5 figures

SECTION 1

Why Does Author's Purpose Matter?

Every time someone writes something — a story, an article, a speech, or even a text message — they have a reason for writing it. That reason is called the author's purpose. Understanding why an author wrote something helps you figure out the main idea, spot hidden opinions, and answer test questions with confidence.

People have thought about the purpose of writing for thousands of years. In ancient Greece, teachers called rhetoricians (experts in persuasive speaking) taught students how to recognize why a speaker chose certain words. Over time, readers and teachers built tools to help us identify what an author is really trying to do.

~350 BC • Aristotle Identifies Three Persuasive Appeals

The Greek philosopher Aristotle taught that speakers use logic, emotion, and credibility to reach their audience. This was one of the first organized ways to study an author's choices.

1450 • The Printing Press Changes Everything

When Gutenberg invented the printing press, books became available to many more people. Readers needed to decide whether a text was meant to teach, entertain, or convince them.

1900s • Schools Teach Critical Reading

By the twentieth century, teachers began asking students to identify the author's purpose as a key reading skill. Standardized tests started including these types of questions.

Today • Author's Purpose in the Digital Age

With social media, ads, blogs, and news everywhere, knowing why someone wrote something is more important than ever. It helps you tell facts from opinions and avoid being tricked.

So the big question every strong reader asks is: "Why did the author write this?" Once you can answer that, you unlock a deeper understanding of any passage you read.

SECTION 2

The Three Main Purposes: PIE

A handy way to remember the three main reasons authors write is the acronym PIE. PIE stands for Persuade, Inform, and Entertain. Almost every passage you encounter on the TACHS will fit into one of these three categories.

1

Persuade

The author wants to change your mind or get you to take action. Look for opinion words like "should," "must," or "best." Examples: editorials, advertisements, speeches.
2

Inform

The author wants to teach you facts or explain how something works. The tone is usually neutral. Examples: textbooks, encyclopedias, news reports.
3

Entertain

The author wants to hold your interest or make you feel something. Look for vivid descriptions, dialogue, and exciting plots. Examples: novels, short stories, poems, jokes.
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KEY TAKEAWAY

Think of it like this: imagine you walk up to a friend. If your friend says, "You have to try this new pizza place!" they are trying to persuade you. If they say, "The pizza place is on Main Street and it opens at noon," they are informing you. If they say, "So I walked in and slipped on the wet floor — cheese everywhere!" they are entertaining you. Same topic, three different purposes!

SECTION 3

Seeing the Author's Purpose

The diagram below shows how the three purposes connect to the types of writing you'll see on the TACHS. Notice how each purpose has its own set of signal words (clue words that help you identify the purpose) and common text types (kinds of writing).

THE PIE MODEL: Author's Purpose at a GlancePERSUADEChange your mindSignal Words:should, must, bestneed to, I believeworst, ought toText Types:• Advertisements• Editorials• Speeches• ReviewsTone:Urgent, passionate,emotional, one-sidedINFORMTeach you factsSignal Words:according to, studiesshow, facts, dataresearch, reportedText Types:• Textbooks• Encyclopedias• News articles• How-to guidesTone:Neutral, factual,straightforwardENTERTAINHold your interestSignal Words:suddenly, whisperedlaughed, felt, onceupon a time, imagineText Types:• Novels / stories• Poems• Plays / scripts• Comic stripsTone:Creative, vivid,humorous, dramaticRemember: PIE = Persuade · Inform · Entertain
This diagram organizes the three main purposes — Persuade, Inform, and Entertain — along with the signal words, text types, and tone that go with each one.

When you see a passage on the TACHS, scan it quickly and ask yourself three questions. Does the author use opinion words like "should" or "best"? That points to persuade. Does the passage stick to facts and data? That points to inform. Does it tell a story or use vivid descriptions? That points to entertain.

SECTION 4

How to Figure Out the Author's Purpose — Step by Step

There is no math formula for author's purpose, but there is a clear process you can follow every time. Think of it as a detective checklist. You gather clues from the passage and then decide which purpose fits best.

1

Read the Title & First Sentence

The title often hints at the purpose right away. A title like "Why You Should Recycle" screams persuade. A title like "The Life Cycle of a Frog" signals inform.
2

Look for Signal Words

Circle or underline opinion words ("best," "must"), fact words ("according to," "studies show"), or story words ("suddenly," "once upon a time"). These are your biggest clues.
3

Check the Tone

Ask: Does the author sound emotional and urgent, calm and neutral, or creative and playful? Tone is like the author's "voice," and it lines up directly with purpose.
4

Identify the Text Type

Is it an ad, a textbook chapter, or a short story? Knowing the type of writing is a shortcut to naming the purpose.
5

State the Purpose in a Sentence

Put it all together: "The author's purpose is to persuade readers that recycling is important." A complete sentence proves you truly understand the purpose.
DECISION FLOWCHART: Finding the Author's PurposeRead the passageDoes the author use opinion words?YESNO→ PERSUADE(should, must, best)Does it stick to facts?YESNO→ INFORM(facts, data, explains)→ ENTERTAIN(story, vivid, creative)Follow the arrows to determine the most likely purpose.
This flowchart walks you through the decision process. Start at the top, answer each question, and follow the arrows to land on the correct purpose.
💡

Test Tip

On the TACHS, you might see the question phrased as "What is the author's main purpose?" or "Why did the author most likely write this passage?" Both are asking the same thing — use the PIE strategy and flowchart to answer.

SECTION 5

Beyond PIE — Looking at Specific Sub-Purposes

Sometimes a test question asks you to be more specific than just "persuade," "inform," or "entertain." Authors can have sub-purposes — smaller, more detailed reasons for writing. The table below breaks down the most common ones you'll see.

Main PurposeSub-PurposeExample Passage
PersuadeTo convince you to agree with an opinion"School lunches should include more fruits and vegetables because…"
PersuadeTo convince you to take action"Sign up today for the beach cleanup!"
InformTo explain a process"The water cycle begins when the sun heats the ocean…"
InformTo describe an event"The 1969 moon landing involved three astronauts…"
EntertainTo create suspense or excitement"The door creaked open, and a shadow slid across the floor…"
EntertainTo make you laugh"The dog wore sunglasses and ordered a smoothie at the drive-through."

Common sub-purposes organized under the three main PIE categories

Keep in mind that a single passage can have more than one purpose. A science article might inform you about climate change and try to persuade you to reduce pollution. On a test, choose the main purpose — the one that best describes the overall passage.

✦

KEY TAKEAWAY

Think of a passage like a sports play. A basketball play might include passing, dribbling, and screening — but the main goal is to score. Similarly, a passage might have several things going on, but there is always one main purpose that drives the whole thing.

SECTION 6

Worked Example — Finding the Author's Purpose

Let's walk through a TACHS-style passage together. Read the short passage below and follow each step.

📝

Sample Passage

"Every student at Lincoln Middle School should join the recycling club. Last year, students who recycled saved over 2,000 pounds of paper from going to the landfill. If more students pitch in, we could double that number. Recycling is the easiest way to help our planet. Don't sit on the sidelines — sign up this Friday!"

Determining the Purpose — Step by Step

  1. 1

    Step 1 — Read the Title & First Sentence

    There is no title given, so look at the first sentence: "Every student at Lincoln Middle School should join the recycling club." The word "should" is a strong opinion word.
  2. 2

    Step 2 — Look for Signal Words

    Circle the signal words: "should," "easiest way," and "Don't sit on the sidelines — sign up." These are all opinion and action words that try to convince you to do something.
    Signal words found: should, easiest, sign up
  3. 3

    Step 3 — Check the Tone

    The author sounds urgent and passionate. Phrases like "Don't sit on the sidelines" create a sense of urgency. This is not a calm, neutral textbook tone.
    Tone: urgent and passionate
  4. 4

    Step 4 — Identify the Text Type

    This reads like a short editorial or an announcement trying to get people to join a club. It is not a textbook chapter or a fictional story.
    Text type: editorial / call to action
  5. 5

    Step 5 — State the Purpose

    Put it all together in a clear sentence.
    The author's purpose is to persuade students to join the recycling club at Lincoln Middle School.

Notice how we didn't just say "persuade." We also said what the author wants to persuade readers to do. A complete answer like this will help you on the TACHS.

SECTION 7

Comparing the Three Purposes Side by Side

Some passages can be tricky because they seem to fit more than one purpose. The table below highlights the strengths and limitations of each purpose to help you tell them apart.

FeaturePersuadeInformEntertain
Uses facts?Sometimes, but only to support an opinionYes — facts are the main contentRarely, unless based on a true story
Uses opinions?Yes — opinions drive the passageNo — stays neutralSometimes through characters
Tells a story?Might tell a short story to make a pointUsually notYes — the story IS the point
Emotional language?Strong — designed to move youMinimal — stays calmYes — creates mood and feeling
Call to action?Often — tells you what to doNoNo

How to distinguish the three main purposes when a passage is tricky

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KEY TAKEAWAY

Imagine three TV channels. Channel P (Persuade) is a commercial trying to sell you sneakers. Channel I (Inform) is a documentary about how sneakers are made. Channel E (Entertain) is a comedy movie where someone trips over their sneakers. Same topic — totally different purposes.

SECTION 8

Connecting to Bigger Reading Skills

Figuring out the author's purpose is one piece of a bigger puzzle. Once you know why the author wrote the passage, you can more easily answer other reading comprehension questions, like identifying the main idea, understanding the tone, and spotting bias (one-sided opinions).

Skill You Know NowHow It Connects to Advanced Skills
Identifying purpose (PIE)Leads to analyzing how an author structures an argument (claim, evidence, reasoning)
Spotting signal wordsLeads to recognizing rhetorical devices like repetition, loaded language, and appeals to emotion
Checking toneLeads to evaluating an author's credibility and detecting bias
Naming the text typeLeads to understanding genre conventions and how different formats shape meaning

How author's purpose skills connect to more advanced reading analysis

On the TACHS and in high school, you will be asked to do more than just name the purpose. You will need to explain how the author achieves that purpose — by pointing to specific word choices, evidence, and techniques. Building your PIE skills now gives you a strong head start.

SECTION 9

Practice Problems

Question 1: CONCEPTUAL

What does the acronym PIE stand for when we talk about author's purpose?
Show answer
PIE stands for Persuade, Inform, and Entertain. These are the three main reasons an author writes a passage. "Persuade" means the author wants to change your mind or get you to act. "Inform" means the author wants to teach you facts. "Entertain" means the author wants to hold your interest or make you feel something.

Question 2: BASIC CALCULATION

Read the following sentence: "The Amazon Rainforest covers about 2.1 million square miles and is home to roughly 10% of all species on Earth." What is the author's most likely purpose?
Show answer
The author's purpose is to inform. The sentence presents facts and statistics ("2.1 million square miles" and "10% of all species") without sharing any opinion or telling a story. There are no signal words like "should" or "best," and the tone is neutral and factual. This is a classic informational sentence.

Question 3: INTERMEDIATE

Read the passage: "Lila crept down the hallway, her heart hammering in her chest. The floorboards groaned under every step. Behind her, something heavy dragged across the floor. She didn't look back." What is the author's purpose, and what clues helped you decide?
Show answer
The author's purpose is to entertain the reader by creating suspense and fear. The clues include vivid descriptions ("heart hammering," "floorboards groaned"), a named character (Lila), and a mysterious, exciting storyline. The passage uses creative, story-like language rather than facts or opinions. These are all classic signs of writing meant to entertain.

Question 4: APPLIED

You read an article that begins: "Cell phones should be banned during school hours. Studies show that students who keep their phones in their lockers score 15% higher on tests. Our school must take action now before grades drop even further." A classmate says the purpose is to inform because it includes a statistic. Do you agree or disagree? Explain your reasoning.
Show answer
You should disagree. Even though the passage includes a fact (the 15% statistic), the main purpose is to persuade. The signal words "should be banned" and "must take action now" are strong opinion phrases. The statistic is used as evidence to support the author's opinion, not just to share neutral information. When facts are used to back up an opinion, the overall purpose is persuasion, not information.

Question 5: CRITICAL THINKING

A magazine article about endangered sea turtles includes beautiful descriptions of turtles swimming in the ocean (entertaining), scientific data about declining populations (informing), and a final paragraph asking readers to donate to a conservation fund (persuading). If a test asks for the author's MAIN purpose, how would you decide which one to pick? Explain your thinking process.
Show answer
When a passage has multiple purposes, you need to identify the main purpose — the one that drives the whole article. Ask yourself: "What does the author want me to DO or THINK after reading this?" In this case, the vivid descriptions pull you in and the data supports the cause, but everything builds toward the final request to donate. That makes persuade the main purpose. The entertaining descriptions and informational data serve as tools to support that persuasive goal. Always look at the ending and the overall direction of the passage to find the primary purpose.

SUMMARY

Summary — Determine the Author's Purpose

Summary

Every passage you read on the TACHS was written for a reason. Use the PIE strategy to identify that reason: the author is either trying to Persuade you (change your mind or get you to act), Inform you (teach you facts), or Entertain you (hold your interest with a story or humor). To figure out which one, look for signal words, check the tone, and identify the text type.

When a passage seems to have more than one purpose, focus on the main purpose — the one that best describes the overall goal of the writing. State your answer in a complete sentence that names both the purpose and the topic: "The author's purpose is to [persuade/inform/entertain] the reader about [topic]." This skill connects to bigger reading skills like identifying main ideas, spotting bias, and analyzing arguments — all of which you'll use in high school and beyond.

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