Educerie · SAT · Reading and Writing
Craft and Structure · CS.2 Text structure and purpose
What you must be able to do
| You must be able to | What it looks like on the test |
|---|---|
| Say a passage's purpose as an action | Which choice best states the main purpose of the text? |
| Say what one sentence does in its paragraph | …the function of the underlined sentence in the text as a whole? |
| Describe a text's overall structure | Which choice best describes the overall structure of the text? |
| Reject accurate summaries | The most common wrong option is a correct summary of content |
1The idea in one paragraph
There are two questions you can ask about any passage: what is it about, and what is it doing. This skill asks the second, and the wrong options answer the first. The right answer always starts with a verb of doing — illustrates, qualifies, challenges, introduces, contrasts, explains, traces — and if your answer begins "the text is about", you have answered the wrong question. Content is the topic; purpose is the job.
Before you look down, finish this sentence: "This passage exists in order to ______." One verb, then an object.
2The verbs that answer these questions
| Verb | The passage is… |
|---|---|
| introduces | presenting something the reader is assumed not to know |
| illustrates | giving an instance of a general point |
| explains | giving the mechanism or reason behind something |
| traces | following a development through time |
| contrasts | setting two things against each other |
| qualifies | accepting a claim but limiting it |
| challenges / questions | pushing against an existing view |
| evaluates | weighing strengths and weaknesses |
| describes | presenting features without arguing |
Learn these and most options become classifiable at a glance. Two options with the same verb differ on the object; two with different verbs differ on the job.
3Function questions: what this sentence does for the rest
When a sentence is underlined and the stem asks its function, ignore whether it is interesting. Ask what the passage loses if you delete it.
Common functions: it states the claim the rest supports; it gives the example for the claim before it; it introduces the objection the next sentence answers; it supplies the background the argument needs; it qualifies the claim just made; it draws the conclusion.
The trick is to read the sentence before and the sentence after the underlined one. A sentence's function is a relationship, and relationships need neighbours.
4Structure questions: the shape of the whole
Which choice best describes the overall structure of the text? The options are two- or three-part descriptions: It presents a theory, then describes an experiment that undermines it.
Test each half separately. A wrong option usually gets the first half right and the second half wrong, because the first half is the easy one. If the option says the text ends by proposing a solution and the text ends by restating the problem, it fails no matter how good its opening clause is.
5Where the purpose lives
The turn. But, however, in fact, more recently, what is less well known. Whatever follows the turn is usually the point of the passage, and the material before it is set-up.
The evaluative sentence. Description is neutral; purpose shows up in words that judge — only, surprisingly, limited, overstated, rarely.
The last sentence. In a short passage the writer usually lands there. A passage whose last sentence is a question is very often raising a problem rather than solving it.
6The three wrong families
| Family | What it looks like |
|---|---|
| Accurate summary | Retells the content with no verb of doing |
| Right verb, wrong object | Challenges — but challenges something else |
| Too large | Attributes a purpose to the passage that belongs to the whole field |
Where points are lost
- Answering the topic. If your answer has no verb of doing, it is the wrong kind of answer.
- Reading the underlined sentence alone on a function question. Read its neighbours.
- Accepting an option on its first half. Structure options break in the second half.
- Picking the option that mentions the most content. Purpose is not coverage.
- Missing the turn. The set-up before however is not the purpose.
- Confusing what the researcher did with what the passage does. The passage may describe an experiment while its own purpose is to challenge an assumption.
Read it right
- Read the passage and find the turn.
- Finish "This passage exists in order to ______" with one verb.
- On a function question, read the sentences either side of the underlined one.
- Classify each option by its verb, then check its object.
- On a structure question, test each half of the option separately.
Try it
Q1. Most accounts of the 1908 flood describe it as a single event. The parish registers, however, record two crests eleven days apart, and the second — smaller, and almost unremarked at the time — did far more damage, because it arrived while the repairs were still open.
Which choice best states the main purpose of the text?
A) To describe the damage caused by a historical flood. B) To correct a common account of an event by introducing overlooked evidence. C) To argue that parish registers are more reliable than published histories. D) To explain how flood repairs were carried out in 1908.
Q2. In the same text, consider the underlined phrase smaller, and almost unremarked at the time.
Which choice best describes the function of that phrase in the text as a whole?
A) It concedes a limitation of the evidence the writer relies on. B) It sharpens the point that the more damaging crest was the less noticed one. C) It explains why the parish registers recorded two crests rather than one. D) It provides a chronological detail needed to date the second crest.
Q3. The alloy was developed for aircraft, where its weight mattered more than its cost. Its second life, though, has been domestic: it now appears in cookware, bicycle frames and prosthetics, none of which could have justified its development and all of which depend on it.
Which choice best describes the overall structure of the text?
A) It introduces a material, then lists the industries that first funded it. B) It describes an original purpose, then contrasts it with the uses that followed. C) It presents a problem, then proposes a solution to it. D) It traces a material's development from laboratory to factory.
In one breath
Ask what the passage is doing, not what it is about, and answer with a verb: introduces, illustrates, qualifies, challenges, contrasts, traces. The set-up before the turn is not the purpose; whatever follows but or however usually is. On a function question read the neighbouring sentences, because a function is a relationship, and on a structure question test each half of the option separately — the wrong ones are almost always right in their first clause.
Answers
Q1. B. the turn at "however", and the overlooked second crest The passage exists to replace the single-event account using evidence most accounts miss. A summarises content and names no job. C generalises one source's usefulness into a claim about sources — too large. D takes a supporting detail as the purpose.
Q2. B. the phrase supplies the contrast the sentence turns on Smaller and unnoticed, yet more damaging — the phrase is what makes the finding surprising. A misreads a fact about the flood as a hedge about evidence. C explains nothing about the registers. D is a chronological reading the phrase does not carry; the dating is done by "eleven days apart".
Q3. B. original purpose, then contrast with later uses The "though" is the hinge. A gets the first half roughly right and the second wrong — the domestic uses did not fund it. C finds a problem and a solution that are not there. D describes a journey through time the passage does not trace; it contrasts two eras rather than following a development.
Educerie · written from the published College Board* Assessment Framework for the Digital SAT Suite *(Craft and Structure, skill/knowledge testing point "Text Structure and Purpose"). All passages, options and explanations are original Educerie text. Last reviewed 12 September 2026.
Check your understanding
The main ideas of this note. Tick each one you could do now, in an exam, without looking back up. Anything you cannot tick yet is the part to read again.