LSAT Complete the Argument questions: finishing someone else's sentence

A Complete the Argument question gives you a passage that stops mid-sentence, usually with a blank at the end, and asks which answer most logically completes it. Stems read "which one of the following most logically completes the argument".

The format is unusual and the task underneath is not. These are almost always Inference questions or Assumption questions wearing a different costume, and which one depends entirely on the word immediately before the blank.

Read the connecting word first

If the blank follows "therefore", "so", "thus", "hence", or "it follows that", you are completing a CONCLUSION. The answer must be something the passage supports — this is an Inference task, and the safest answer is usually the most modest one that the evidence actually reaches.

If the blank follows "because", "since", "for", or "after all", you are supplying EVIDENCE for a conclusion already stated. That is an Assumption task: the answer has to be the missing support, and it usually needs to be strong enough to close the gap rather than merely relevant to it.

Two words, two opposite jobs, and reading past them is the single most common way to lose this question type. Find the connector before you read a single answer.

Then look at what the passage set up but never used

These passages usually introduce a comparison, a contrast, or a piece of data that is left dangling right up to the blank. That dangling element is nearly always the point. If a passage carefully distinguishes two groups and then trails off, the answer almost certainly turns on that distinction.

• Overshooting on a 'therefore' blank. An answer stronger than the evidence supports — the most frequent trap, because a bold completion reads as satisfying.
• Undershooting on a 'because' blank. A true, relevant fact that does not actually support the conclusion.
• Restating the passage. Adds nothing, contradicts nothing, and completes no argument.
• Answering the wrong task. A perfectly good assumption offered where a conclusion was needed, or the reverse — which is exactly what skipping the connector produces.
• Introducing a new comparison the passage never made.