Intransitive verb

An intransitive verb is complete without a direct object: the action does not pass on to anything, so the sentence needs only a subject — 'the engine stalled'.

The engine stalled. Nothing follows the verb, and nothing needs to. Ask stalled what? and the question makes no sense, which is the test for an intransitive verb.

Many verbs switch depending on the sentence. She flew to Lisbon is intransitive; She flew the plane is transitive. A handful are strictly one or the other, and those are where the errors cluster.

The famous pair is lie and lay. Lie is intransitive — you lie down, nothing else involved. Lay is transitive and needs an object — you lay something down. The confusion is made worse by the past tense of lie being lay: yesterday she lay down is correct, and she laid down is not, unless the sentence goes on to say what she laid. The same distinction separates rise from raise, and sit from set.

Stylistically, intransitive verbs make short, self-contained sentences — The lights failed. Nobody moved. — and a run of them reads as clipped, even shocked. That is useful at the end of a scene and monotonous over a page.