One of the main difficulties that students of Italian have is the use of the imperfect (imperfetto) vis-à-vis the present perfect (passato prossimo) to express past actions. Typically, the imperfect is used to express actions that are habitual; that describe a feeling, physical traits or the weather; or refer to a single moment in a past action. The present perfect typically describes a whole action (now completed) rather than a moment in that action. Consider these examples.
Ieri volevo andare al parco, ma ha cominciato a piovere e allora sono rimasta a casa.
Yesterday I wanted to go to the park but it started to rain so I stayed home.
Da bambini, eravamo tutti e tre biondi.
As children, the three of us were blond.
Andavamo a scuola in bicicletta.
We used to ride the bike to school.
Non è venuta al funerale perché era già molto depressa.
She didn’t come to the funeral because she was already very depressed.
La settimana scorsa faceva troppo freddo per andare alla spiaggia.
Last week it was too cold to go to the beach.
Sapevo che non le piacevano i film violenti e allora l’ho portata a vedere un film comico.
I knew she didn’t like violent films so I took her to see a comedy.
Temevamo che l’idraulico non potesse venire fino a domani a riparare il guasto e invece è venuto subito.
We were afraid the plumber would not come till tomorrow to fix the fault but he came straight away [note the use of the imperfect both in the indicative and the subjunctive].
Stavamo cenando quando hanno bussato alla porta i nostri vicini.
We were having dinner when our neighbours knocked on the door.