Breakdown of L'expert a affirmé que l'accident s'y était passé.
être
to be
avoir
to have
l'accident
the accident (m)
se passer
to happen
Questions & Answers about L'expert a affirmé que l'accident s'y était passé.
Why do we use the plus-que-parfait (était passé) here instead of the passé composé?
This sentence uses reported speech. Because the main verb (a affirmé) is in a past tense, the event being reported must shift one step further back in time. The original action backshifts from the passé composé to the plus-que-parfait to show it had already happened before the expert spoke.
Why does the plus-que-parfait here use était instead of avait?
The verb being used is se passer (to happen), which is a reflexive verb. In French, all reflexive verbs use être as their auxiliary in compound tenses, including the plus-que-parfait.
Why are the pronouns ordered as s'y?
Doesn't the verb passer usually mean to pass or to spend time?
It does! However, when you make it reflexive as se passer, the meaning changes entirely to mean to happen or to take place.