LSAT RC Inference Answers: Why 'Must,' 'Could,' and 'Suggests' Mean Very Different Things

In LSAT Reading Comprehension, two answer choices can say essentially the same thing about the passage — and one can be right while the other is wrong. Often the difference is a single modal verb: 'must,' 'can,' 'could,' 'would,' or 'suggests.'

These words set the standard the answer has to meet. An answer that says the passage 'suggests' something has to clear a much lower bar than one that says the passage 'proves' or that something 'must be true.' Getting the standard wrong — reading an answer as if 'could' and 'must' mean the same thing — leads to consistently missed questions regardless of how well you understood the passage.

Think of inference strength as a spectrum. At one end, the strongest claims: 'must be true,' 'is,' 'proves.' These require the passage to guarantee the statement — nothing in the passage can be consistent with the statement being false.

In the middle: 'supports,' 'suggests,' 'indicates.' These require a genuine basis in the passage — not just speculation — but don't require a guarantee. The passage needs to make the claim more likely than not.

At the weak end: 'could be true,' 'might be,' 'is possible.' These only require that the statement isn't ruled out by the passage. If the passage doesn't contradict it, it passes.

For 'must be true' and equivalent questions (which the LSAT RC section tests frequently), the correct answer has to be guaranteed by the passage. Before reading the choices, ask yourself: what does this passage prove outright, with no ambiguity?

A common trap: an answer that's probably true given the passage but isn't guaranteed. The passage says scientists believe X is more common in cold climates. An answer that says X is most common in the coldest climates is probably true based on that premise — but 'most common in the coldest climates' is a stronger statement than 'more common in cold climates.' It adds a superlative ('most,' 'coldest') that the passage never established.

Whenever you see a superlative — 'most,' 'least,' 'always,' 'never,' 'all,' 'only' — in a must-be-true answer, verify it against the passage carefully. These words set very high bars, and trap answers on must-be-true questions routinely overshoot what the passage actually says.

Author attitude questions ask about the author's view or tone. The answer choices often use similar hedges: 'is skeptical of,' 'is enthusiastic about,' 'has reservations about,' 'is dismissive of.'

The word strength here matters enormously. 'Dismissive' implies the author thinks the view is not worth serious consideration. 'Skeptical' implies the author doubts but takes it seriously. 'Cautiously optimistic' implies mild positive lean. These aren't interchangeable.

One technique: for each attitude answer, ask 'what would the passage have to sound like if the author truly held this attitude?' Then check whether the passage actually sounds that way. An author who is 'dismissive' would use stronger language than one who is merely 'uncertain.' If the passage uses hedged, balanced language, any answer with strong negative attitude words ('dismissive,' 'hostile,' 'condemns') is almost certainly wrong.

When reviewing wrong answers on RC, specifically look for overreach — the answer says something stronger than the passage supports. Write down the passage sentence that was supposed to support each wrong answer, then write down the answer's claim. Look for any word in the answer that adds something the passage sentence didn't say.

Common overreach patterns: 'always' when the passage said 'often.' 'All' when the passage said 'most.' 'Proves' when the passage said 'evidence suggests.' 'The primary reason' when the passage listed one reason among several.

Catching these patterns in review makes you better at spotting them in the five answer choices on test day — which is exactly when you need to notice a single word difference before you waste time on a wrong answer.