Italian B1: Passato prossimo or imperfetto? · Words

The passato prossimo tells what happened, a finished event: Ieri ho visto Luca. The imperfetto sets the scene: background, habits, states, what was going on. Together: Mentre camminavo (the scene), ho incontrato Luca (the event). Some verbs change meaning: sapevo (I knew), ho saputo (I found out); conoscevo (I knew someone), ho conosciuto (I met someone).