Agreement of the past participle
When the auxiliary is être, the past participle agrees with the subject — like an adjective.
| Subject | ||
|---|---|---|
| il | il est allé | — |
| elle | elle est allée | + e |
| ils | ils sont allés | + s |
| elles | elles sont allées | + es |
"Ma sœur est partie hier." · "Mes parents sont rentrés tard."
With a mixed group, the masculine plural wins, even if there are nine women and one man: Les invités sont arrivés.
*With avoir, there is no agreement with the subject.* This is the whole point of learning the two auxiliaries apart:
- Elle est venue. (être — agrees)
- Elle a mangé. (avoir — does not)
Reflexive verbs take être, so they agree in the ordinary case: "Elle s'est levée." · "Elles se sont reposées."
Most of this agreement is silent. Allé, allée and allés all sound identical; only mort/morte and a handful of others change the sound. It is therefore a writing problem far more than a speaking one — which is exactly why the reading exam tests it and conversation does not.
Knowing the rule is not the same as producing it.
This page explains the pattern. The track drills it: the point arrives inside a mini-dialogue, then production marked against a CEFR descriptor, then a module test that returns you to your two weakest sessions if you miss it.