GMAT Critical Reasoning tests your ability to analyze arguments — to identify what they assume, what would strengthen or weaken them, and what conclusions follow from the evidence. Strong vocabulary directly supports this ability: every argument structure has a vocabulary, and test-takers who know that vocabulary reason more precisely and answer questions faster.
This guide covers the vocabulary of logical argumentation as it appears in GMAT Critical Reasoning — both in the passage stems and in the answer choices that require precise discrimination.
The Anatomy of a GMAT Argument
Every GMAT Critical Reasoning passage is a short argument consisting of:
- Premise(s): The evidence or facts offered in support of the conclusion
- Conclusion: The main claim the argument is trying to establish
- Assumption: An unstated premise that the argument depends on but doesn't mention
- Inference: A conclusion that can be drawn from the premises beyond the stated conclusion
Knowing these components and the vocabulary associated with each makes argument analysis systematic rather than intuitive — which is far more reliable under time pressure.
Vocabulary for Argument Components
| Word | Definition | Example in GMAT Context |
|---|---|---|
| Premise | A statement offered as evidence for a conclusion | Identify the premise that, combined with the conclusion, reveals the unstated assumption. |
| Conclusion | The claim the argument seeks to establish | The conclusion of the argument is that the new policy will reduce costs. |
| Assumption | An unstated premise the argument requires | Which of the following is an assumption on which the argument depends? |
| Inference | A conclusion drawn from premises | Which of the following can be properly inferred from the statements above? |
| Corollary | A consequence following naturally from a proved proposition | A corollary of the study's findings is that the current guidelines need revision. |
| Presuppose | To require as a prior condition | The argument presupposes that all employees have equal access to the training program. |
| Analogous | Comparable in certain respects | The researcher drew an analogous conclusion from a study in a different industry. |
| Extrapolate | To extend conclusions beyond observed data | The consultant extrapolated from the pilot program to predict company-wide results. |
| Qualify | To limit or modify the force of a claim | The author qualifies the conclusion by noting that it applies only to mature markets. |
| Bolster | To support and strengthen | Which of the following, if true, most bolsters the argument's conclusion? |
Vocabulary for Logical Flaws
GMAT Critical Reasoning includes "Flaw" and "Weaken" question types where you must identify what is logically wrong with the argument. Knowing the names and descriptions of common logical fallacies helps you recognize the flaw faster.
False dichotomy: The argument presents only two options when more exist. "Either we invest in new equipment or we fall behind our competitors" — perhaps there is a third option (licensing, outsourcing).
Circular reasoning: The conclusion is used as a premise. "The policy must be good because it produces good outcomes." The "good outcomes" need independent evidence.
Post hoc: Assuming that because A happened before B, A caused B. "Crime rates fell after the new police chief took office, therefore the chief caused the reduction." Other factors may explain the reduction.
Hasty generalization: Drawing a broad conclusion from insufficient evidence. Inferring that all customers prefer online service from a survey of 20 customers.
Ad hominem: Attacking the person making an argument rather than the argument itself. "We should disregard his environmental concerns because he owns a large house."
Straw man: Misrepresenting an opponent's position to make it easier to attack. Characterizing a moderate proposal as an extreme one before refuting the extreme version.
Vocabulary for Strengthening and Weakening Arguments
| Word | Definition | Appears In |
|---|---|---|
| Corroborate | To confirm with additional evidence | Strengthen question answer choices |
| Undermine | To weaken the foundation of | Weaken question answer choices |
| Mitigate | To make less severe | Answer choices that partially weaken concerns |
| Substantiate | To provide proof for | Strengthen question stems |
| Invalidate | To make legally or logically void | Weaken question; stronger than "undermine" |
| Predicate | To base an assertion on | Assumption questions: the argument is predicated on... |
| Contend | To maintain or assert | Summarizing the argument's conclusion: "the author contends that..." |
| Stipulate | To specify as a condition or requirement | Assumption questions: the argument stipulates that... |
High-Value Vocabulary in GMAT CR Answer Choices
Answer choices for Critical Reasoning questions use precise vocabulary that must be read carefully. These words frequently appear in choices and require exact understanding:
"Is likely to" vs. "would": "Is likely to" makes a probabilistic claim; "would" makes a certain claim. An answer choice using "would" that is presented as only probable is using the wrong modal — this can make a generally correct answer technically wrong.
"Necessary" vs. "sufficient": A necessary condition must be present for a result but doesn't guarantee it. A sufficient condition guarantees a result but isn't the only way to achieve it. GMAT questions frequently test whether test-takers confuse these.
"Could explain" vs. "explains": "Could explain" only requires that the answer is possible. "Explains" requires that the answer is actually true and sufficient. Answer choices using "could explain" are easier to accept; those using "explains" make a stronger claim.
"Most strengthens" vs. "strengthens": You're looking for the choice that does the most work — not just any choice that adds some support. Eliminate choices that provide irrelevant support or support a different conclusion than the one in the argument.
Causal Vocabulary: The Most Tested Relationship in CR
The majority of GMAT Critical Reasoning arguments involve causal claims — "X caused Y" or "doing X will produce Y." The vocabulary of causation is therefore the most important to master.
Catalyst: Something that triggers or accelerates a process. Precipitate: To cause to happen suddenly or prematurely. Engender: To produce or give rise to. Attributable to: Caused or explained by. Commensurate with: Corresponding in size or degree to — useful for testing whether the effect is proportional to the cause.
For broader GMAT vocabulary coverage, see our guides on GMAT's 200 most-tested words and Sentence Correction grammar rules.
FAQ
How much of GMAT Critical Reasoning depends on vocabulary?
Vocabulary plays a supporting role — the primary skill tested is logical reasoning. However, misreading even one word in an answer choice (e.g., confusing "necessary" and "sufficient," or misreading the scope of a modal like "might" vs. "will") can and does cost points. Strong vocabulary minimizes these errors.
What is the most common type of Critical Reasoning flaw on the GMAT?
Assuming that correlation implies causation is the most commonly tested logical flaw. The argument observes that two things happen together or in sequence and concludes that one caused the other — without eliminating alternative explanations or establishing mechanism. Recognizing this pattern quickly is one of the highest-ROI skills in GMAT CR preparation.
What is the difference between "necessary assumption" and "sufficient assumption" questions?
A "necessary assumption" question asks what the argument must assume to be valid — what must be true for the argument to hold. A "sufficient assumption" question asks what single additional premise, if true, would make the conclusion logically guaranteed. Necessary assumptions are weaker (the argument requires them but they may not fully justify the conclusion). Sufficient assumptions are stronger (they logically guarantee the conclusion).
How should I approach answer choices I don't fully understand?
Break the answer choice into its component claims. Identify the subject, the verb, and any quantifiers (all, some, most, none). Check whether the modal verb is strong (will, does, must) or weak (might, could, may). Eliminate choices where any component contradicts the passage or is irrelevant to the argument's conclusion.
Practice These Words With Visual Flashcards
PassGREGMAT's visual flashcard system uses real photos to lock vocabulary into long-term memory. Free to start — no account needed.