on en avait parlé

we had talked about it

→ on
phrase Rare #34,950
we had talked about it “On” commonly means “we” here, and “en” refers to something previously mentioned or understood from context. This is the past perfect (pluperfect) form of “en parler.”
FR: On en avait parlé hier, mais personne ne s’en souvenait.
EN: We had talked about it yesterday, but no one remembered it.

On en avait parlé, il te mate tout le temps.

We talked about it, he's always staring at you.

— La Vie d'Adèle - Chapitres 1 et 2 (2013)

On en avait parlé, mais il n'en voulait pas.

We had talked about it, but he didn't want it.

— Assurance sur la mort (1944)

Je pensais qu'on en avait parlé.

I thought we talked about it.

On en avait parlé.

We had talked about it.

— Anatomie d'une chute (2023)