Bonjour !
Avant, nous ____ les oiseaux chanter dans le jardin.
❌ A. avons entendu
B. entendions
❌ C. entendait
❌ D. entendons
"Avant" means "Before" so it is focement a conjugated verb in the past tense.
So A and B, both are forms of the conjugated verb "entendre" (to hear) but the first is not alone, it's with an auxiliaire avoir (to have) that means it's a "composed" time (temps "composé").
A is "passé composé" (auxiliaire (avoir or être) + verbe)
B is "passé simple", this is the one I think your teacher is waiting for
Have a good day, gl :)
