English builds every past tense with the same helper verb, have. French splits the job between two: avoir, the default nearly every verb reaches for, and être, reserved for a specific, memorizable group of verbs about movement or change of state — plus every reflexive verb, without exception. Picking the wrong one doesn't just sound off; with être verbs, the past participle also has to agree with the subject.
Avoir is the default helper for the passé composé — nearly every verb uses it. Être is reserved for a small set of movement and change-of-state verbs, plus every reflexive verb.
The default auxiliary, used by most verbs
A specific set of movement/change verbs, plus every reflexive verb
Elle est sortie hier soir, mais elle a sorti la poubelle avant de partir.
She went out last night, but she took out the trash before leaving.
Sortir, monter, descendre, and a few other movement verbs take être when they're intransitive (no direct object) but switch to avoir the moment they take one — sortir la poubelle means "take the trash out," not just "go out."
A handful of these movement verbs swing back to avoir the instant they take a direct object — the auxiliary tracks whether the verb is being used transitively, not just which verb it is.
| Verb | Être | Avoir |
|---|---|---|
| sortir | est sorti(e)went out (no direct object) | a sortitook [something] out |
| monter | est monté(e)went up | a montécarried [something] up |
| descendre | est descendu(e)went down | a descendubrought [something] down |
| passer | est passé(e)went by, dropped in | a passéspent [time], passed [something] along |
Take the quiz and see if you can pick avoir or être for the passé composé every time.