Text Structure and Purpose

Identify the main purpose of a passage or the function of one sentence, and describe how the passage is organized. It is part of Craft and Structure in the Reading and Writing section. The book teaches it in Chapter 6, Text Structure and Purpose, with 15 practice questions, and tests it 8 more times across the two full-length practice tests.

About Chapter 6

Text Structure and Purpose questions ask what a text is doing, not only what it says. Every author has a job in mind: to describe something, to argue a point, to challenge an idea or to capture a moment in a story. These questions ask you to name that job for the whole text, for one underlined sentence, or for the order of the parts. Once you can label what each sentence does, these questions become predictable.

What the question looks like

Text Structure and Purpose is part of the Craft and Structure domain, so these questions appear early in each Reading and Writing module, usually right after the Words in Context questions. Each one has a short passage, sometimes a poem, and one of three questions.

  • Main purpose; Question: Which choice best states the main purpose of the text?; What you are naming: Why the whole text was written
  • Underlined function; Question: Which choice best describes the function of the underlined portion in the text as a whole?; What you are naming: The job that one sentence or phrase does for the text
  • Overall structure; Question: Which choice best describes the overall structure of the text?; What you are naming: The moves the text makes, in order

The choices usually begin with a verb: "To argue that…," "To describe…," "It introduces…," "It qualifies…." Check that verb first.

How to recognize it

You are in this skill when the question uses the word purpose, function or structure. Do not confuse it with Central Ideas and Details (Chapter 8), which asks for the main idea: what the text says. Main purpose questions ask what the text does. Compare three labels for a short passage about a town that tested a four-day school week:

  • Topic: A four-day school week
  • Main idea: The town's trial found that attendance rose but some families struggled to find childcare.
  • Main purpose: To report the mixed results of a trial

A choice that only names the topic is never enough for a purpose question.

Common traps

  • Topic, not purpose: The choice names what the text is about but not what it does.
  • Wrong verb: "Argue" for a neutral report, or "criticize" when the author only describes.
  • Too narrow: For main purpose, the choice fits one sentence or detail, not the whole text.
  • Wrong neighbor: For underlined function, the choice describes what a different sentence does.
  • Half right: For overall structure, the first part matches but a later part does not, or the order is wrong.
  • Too strong: The choice says "proves," "rejects" or "always" when the text only suggests or qualifies.

Video lessons

Two short lessons from independent YouTube creators, chosen for this skill. The notes are ours; the videos belong to their creators, who are not affiliated with this site.

  • Structure and purpose questions, step by step (Penguin SAT Prep , 11:30). Watch for: Describing what each sentence does before matching a choice.
  • The function of an underlined sentence (SAT Mastermind, 5:28, captions). Watch for: Naming the job of one sentence in the passage as a whole.

Practice this skill

The full method, worked examples and 15 practice questions with every answer choice explained are in Chapter 6 of the book and in the study workspace, where an AI coach can talk you through each one.

Independence

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