Find the proposition that organizes a passage, then preserve its scope and purpose in a concise summary.
GRE General Test45 min study guide10 indexed sections
BY THE END, YOU CAN
Distinguish a topic from a central claim.
Explain why an example supports rather than replaces the main idea.
Choose a purpose verb supported by the author’s actual work.
Summarize a qualified or multi-paragraph argument without erasing its limits.
BEFORE YOU START
Recognize subjects and predicates in sentences.
Distinguish a fact from an explanation or judgment.
Original educational lesson. Work through the examples before revealing the practice answers. This original lesson supports current GRE General Test study; it does not reproduce official questions, certify a writing score or predict test content.
LEARN THROUGH ORIGINAL PRACTICE
Original GRE-style worked examples and practice
All teaching passages, writing prompts, examples and exercises in this lesson are original. No official ETS questions, prompts or explanations are reproduced. Current structure and observed public sample metadata are separate from this original teaching; no official score or question probability is implied.
01 / UNDERSTAND & APPLY
A subject is not yet a main idea
A passage can be about urban gardens while arguing that their ecological benefits depend on maintenance. “Urban gardens” identifies the subject; “garden benefits depend on maintenance” states what the author wants the reader to understand. A main-idea answer normally combines a subject, a relationship or judgment, and any indispensable limit. Ask what changed between your understanding before and after reading.
The title you could give a passage may be much broader than its claim. Conversely, one vivid finding may be too narrow. To test a proposed main idea, explain how each substantial part of the passage contributes to it. If a whole paragraph has no plausible role, the proposed summary may omit the argument’s center. All passages, scenarios and exercises in this lesson are original educational material, not official GRE items.
ORIGINAL WORKED EXAMPLE
A topic and a thesis
Original passage: Rooftop gardens are often praised for cooling buildings. Yet shallow soil dries rapidly, reducing evaporation precisely during heat waves. Their cooling value therefore depends partly on irrigation design. State the main idea.
Name the topic: rooftop gardens and cooling.
The first claim introduces a favorable expectation; “Yet” adds a limitation.
The final sentence integrates both: cooling is conditional on water management.
Avoid “rooftop gardens do not cool buildings,” which turns a condition into a rejection.
Answer Rooftop gardens’ cooling benefits depend in part on irrigation design, especially during heat waves.
02 / UNDERSTAND & APPLY
Purpose describes an intellectual action
Main idea asks what the passage says overall. Purpose asks what the author is doing: explaining a mechanism, comparing accounts, challenging an inference, qualifying a generalization, or advocating a course of action. Choose the narrowest accurate verb. Reporting that a proposal exists is not advocating it; mentioning two theories is not necessarily comparing them systematically.
Purpose also has an object. “To criticize” is incomplete: criticize what, and on what grounds? A passage may criticize a measurement rather than reject an entire theory. Watch answers whose verb is defensible but whose object is exaggerated.
ORIGINAL WORKED EXAMPLE
Criticizing a measure
Original passage: The archive counts only printed pamphlets. Because handwritten notices circulated alongside them, the count cannot establish the total volume of public debate. Select one primary purpose: A explain printing technology; B question an inference from a limited archive; C deny that pamphlets mattered; D compare handwriting styles; E recommend ending archival research.
The evidence concerns what the archive excludes.
The disputed conclusion concerns the total volume of debate.
B captures the action and the restricted target.
A and D introduce subjects not developed; C and E enlarge a measurement criticism into sweeping rejection.
Answer B: question an inference from a limited archive.
03 / UNDERSTAND & APPLY
Separate the organizing claim from its support
Details can be memorable because they are concrete, numerical, or surprising. Importance to the argument is different from memorability. A sentence is structurally central when other sentences supply reasons for it, limit it, or answer a question it raises. Examples are often replaceable: another suitable case could play the same role without changing the thesis.
Do not count lines mechanically. A short conclusion can organize a long illustration. Nor should you always take the final sentence: the end may be a narrow implication. Track support relations rather than position alone.
ORIGINAL WORKED EXAMPLE
An example supports a broader mechanism
Original passage: Reorganizing a workspace can improve access without increasing its size. In one repair shop, moving frequently used tools closer to the benches shortened retrieval time despite unchanged floor area. Better arrangement, rather than expansion, can therefore ease some space-related difficulties. Select one summary: A Every workshop should become smaller. B Changing arrangement can improve access without adding space. C Retrieval time depends only on shop size.
The opening sentence states the general relationship: arrangement can improve access without growth.
The tool relocation illustrates the mechanism by reducing travel to frequently needed objects.
B preserves that relationship and its conditional force.
A invents a universal recommendation; C excludes the arrangement effect the passage illustrates.
Answer B.
04 / UNDERSTAND & APPLY
Compress each paragraph before joining them
For a longer passage, jot a functional phrase for each paragraph: “old explanation,” “new evidence,” “limited conclusion.” Then articulate their relationship. Merely placing three paragraph topics side by side produces an inventory rather than a summary. A good summary might say that new evidence narrows an older explanation without displacing it entirely.
A paragraph’s first sentence can orient you, but transitions, attribution and concluding qualifications can change its role. Revisit the map after reading the whole passage.
ORIGINAL WORKED EXAMPLE
A two-paragraph synthesis
Original passage, paragraph 1: Historians once treated port inventories as direct records of consumer demand. Inventories list goods present, however, including stock that remained unsold. Paragraph 2: Comparing inventories with purchase receipts helps separate availability from actual buying. The comparison is imperfect because many receipts are lost, but it narrows the uncertainty. Summarize both paragraphs in one sentence.
Paragraph 1 identifies a measurement problem: availability is not demand.
Paragraph 2 proposes a partial correction, then limits it.
Preserve both improvement and incompleteness.
Do not claim that receipts fully reveal historical demand.
Answer Port inventories can misrepresent consumer demand, but comparison with surviving receipts can partly reduce that uncertainty.
05 / UNDERSTAND & APPLY
Preserve degree, population and conditions
A summary must preserve the force of the original claim. “May,” “often,” “under these conditions,” and “one contributor” restrict commitment. Replacing them with “always,” “proves,” or “the sole cause” changes the argument. Yet an answer can also be too weak: if a passage establishes that a measurement is unreliable in a defined situation, “raises an unrelated possibility” may fail to capture its definite conclusion.
Scope has several dimensions: who or what is covered, when, how confidently, and compared with what baseline. Check these separately rather than rejecting every strong-sounding word. A universal answer can be correct if the passage supports a universal claim.
ORIGINAL WORKED EXAMPLE
A qualified main claim
Original passage: In the three nurseries studied, shaded seedlings survived transplanting more often than exposed seedlings. Shade may therefore improve transplant survival for this species, although trials in other climates are needed. Select one: A Shade guarantees seedling survival. B Shade may improve this species’ transplant survival, but broader testing is needed. C All plants require shade. D Climate has no effect on seedlings.
The population is one species in three nurseries.
The conclusion uses “may” and explicitly requests broader testing.
B preserves both the positive implication and its boundary.
A and C universalize; D contradicts the reason further climates matter.
Answer B.
06 / UNDERSTAND & APPLY
Audit attractive answers rather than matching words
A wrong main-idea answer can repeat nearly every important noun. Inspect its logical relationship: does it reverse cause and effect, exchange author and critic, or confuse evidence with the conclusion? Another common trap is a statement that is true somewhere in the passage but cannot explain the passage as a whole.
Use a two-part test: coverage and fidelity. Coverage asks whether the answer encompasses the major argument. Fidelity asks whether each meaningful part is supported. An expansive answer may pass coverage while adding unsupported motives; a precise detail may pass fidelity while missing coverage.
Too broad: expands one study to an entire field.
Too narrow: names only an illustration.
Too strong: turns a possibility into certainty.
Wrong role: reports an opponent’s position as the author’s conclusion.
Wrong purpose: turns explanation into recommendation.
07 / UNDERSTAND & APPLY
Original practice: identify the center
For each selection question, choose exactly one answer. For the short-response questions, compare meaning rather than identical wording.
ORIGINAL PRACTICE · 1
Original passage: A new catalog makes rare manuscripts easier to locate. It does not resolve disputed authorship, since its entries repeat earlier attributions. Best main idea: A Catalogs settle authorship. B Improved access does not by itself settle attribution. C Manuscripts should remain uncataloged.
Reveal answer & reasoning
B.
The first sentence grants a benefit, and the second limits what that benefit accomplishes. A contradicts the limit; C invents a recommendation.
ORIGINAL PRACTICE · 2
Original passage: Some observers call the wetland unproductive because it yields little timber. That measure overlooks its flood storage and water filtration. Primary purpose: A broaden the criteria for judging productivity; B describe timber harvesting; C quantify filtration.
Reveal answer & reasoning
A.
The author challenges the adequacy of one evaluative standard by identifying excluded benefits. No harvesting process or quantity is supplied.
ORIGINAL PRACTICE · 3
Original passage: Early maps depict empty inland areas. Those blanks reveal limits of the mapmakers’ information, not necessarily an absence of inhabitants. Write a one-sentence summary.
Reveal answer & reasoning
Blank areas on early maps can reflect missing information rather than uninhabited land.
The central contrast is between a feature of a record and an unwarranted conclusion about reality. A summary about the beauty or accuracy of all maps would miss or enlarge the claim.
ORIGINAL PRACTICE · 4
Original passage: A repair shop moved frequently used tools closer to its benches and reduced retrieval time without adding floor space. The example shows that rearrangement can improve access even when expansion is impossible. Which is a minor supporting point? A Rearrangement can improve access without expansion. B The shop moved tools closer to its benches.
Reveal answer & reasoning
B.
The tool relocation is the concrete supporting detail. The broader claim concerns the possibility of improving access through arrangement rather than additional space.
08 / UNDERSTAND & APPLY
Original practice: scope and purpose under pressure
Read the complete passage before selecting. These short passages isolate particular traps; longer reading requires the same checks across paragraphs.
ORIGINAL PRACTICE · 1
Original passage: A survey found that volunteers at one museum preferred evening training. Since daytime volunteers rarely responded, the result cannot establish the preference of all volunteers. Choose one: A Evening training is unpopular. B Response patterns limit the survey’s generalizability. C Surveys never yield useful information.
Reveal answer & reasoning
B.
The issue is underrepresentation of daytime volunteers. A reverses the observed result, while C expands a specific limitation into a universal judgment.
ORIGINAL PRACTICE · 2
Original passage: Urban birds sometimes sing at higher pitches near busy roads. Noise masking is one possible explanation, although population differences might also contribute. Choose one summary: A Noise is the only cause. B Pitch differences may have more than one explanation. C Birds cannot hear traffic.
Reveal answer & reasoning
B.
The author explicitly keeps two explanations open. B captures that uncertainty without claiming both have been demonstrated.
ORIGINAL PRACTICE · 3
Original passage: A historian first describes a familiar interpretation, then presents letters inconsistent with one part of it, and finally preserves the remainder. Choose one purpose: A discard the entire interpretation; B qualify an interpretation using new evidence; C celebrate letter writing.
Reveal answer & reasoning
B.
The author revises only one part. “Discard the entire” misstates the degree of change; “celebrate” mistakes the evidence’s subject for the intellectual purpose.
ORIGINAL PRACTICE · 4
Original passage: The software detects repeated phrases quickly. Scholars must still decide whether repetition signals influence or coincidence. Explain why “Software has replaced scholarly judgment” is an unsuitable summary.
Reveal answer & reasoning
It erases the passage’s explicit limit on what detection can establish.
The passage distinguishes identifying a pattern from interpreting its significance. A faithful summary recognizes automation’s contribution while retaining the need for judgment.
09 / UNDERSTAND & APPLY
Developed original passage: integrate the full argument
The following passage and question are original educational material. Read the whole passage before answering; the five options deliberately differ in scope, attribution or argumentative role.
Municipal tree inventories often classify a street as well shaded when its trees have large crowns. This measure is easy to standardize: an aerial image can estimate crown area without requiring observations at every hour. It also allows planners to compare many streets quickly. Yet a broad crown does not guarantee that pedestrians encounter shade when they need it. Building orientation, crown height and the route people actually follow can shift the shaded area away from the sidewalk.
A neighborhood study illustrates the distinction. Two streets had similar overhead crown coverage, but afternoon shade fell mostly on parked cars in one and on a heavily used walkway in the other. The study does not show that crown measurements are useless. Such measurements remain informative about vegetation, and repeated images can reveal changes over time. It suggests, instead, that an inventory designed to guide pedestrian cooling should supplement crown coverage with observations tied to walking routes and times of use. The appropriate measure depends on the decision it is meant to inform.
ORIGINAL WORKED EXAMPLE
A complete-passage worked analysis
Select exactly one best main idea: A Aerial images are incapable of providing useful information about urban trees. B Pedestrian cooling decisions require attention to where and when shade occurs, beyond crown coverage alone. C All streets with equal crown coverage provide equal benefits to pedestrians. D Parked cars prevent urban tree programs from succeeding. E Municipalities should replace all standardized inventories with individual complaints.
Paragraph 1 grants crown measurement’s convenience, then distinguishes overhead coverage from experienced shade.
Paragraph 2 supplies a comparison, explicitly preserves the measure’s value, and recommends a purpose-specific supplement.
B covers both the measurement limitation and the decision-oriented correction.
A ignores the explicit concession that inventories remain useful; C asserts the equivalence the example challenges.
D makes parked cars a general cause of failure when they are merely part of an illustration; E invents a replacement method and erases the proposed supplementation.
Answer B.
10 / UNDERSTAND & APPLY
Build a reusable summary routine
After a practice passage, write a summary without looking at the choices, then justify it against the text. If your answer was wrong, diagnose whether you misidentified the central claim, lost a qualifier, or accepted unsupported material in an option. “Read more carefully” is too vague to guide the next attempt.
A useful review sequence is: subject → central relationship → author’s action → essential limit. Compress only after identifying these parts. Shorter is not automatically better: omitting the one condition that distinguishes the author’s view produces an inaccurate summary.
KEEP THE BIG IDEAS
Quick revision
A main idea states the passage’s organizing claim, not merely its subject.
Purpose answers what the author does and to what target.
Test summaries for both whole-passage coverage and textual fidelity.
Keep qualifications and distinguish supporting examples from central claims.
The teaching notes, passages, worked explanations and practice are original. Official references identify the assessment framework and skill scope; they do not endorse this lesson or license official question reproduction.
GRE analytics distinguish current test structure from a small independently classified public sample selection. Writing instruction has no observed prompt-frequency denominator. These are not historical administered-exam frequencies.