A past before the past
You are telling someone about last night and have to say what was already over before that. That is the job of the Trapassato prossimo: the English past perfect (I had already eaten when you arrived). You already know the building blocks: the Imperfetto of avere or essere and the past participle from the Passato prossimo.
What it sounds like
Avevo già mangiato quando sei arrivato.
I had already eaten when you arrived.
Il treno era già partito.
The train had already left.
Non avevo mai visto il mare prima di allora.
I had never seen the sea before then.
How it is built
Take the Passato prossimo and move the auxiliary into the Imperfetto. The choice between avere and essere and the agreement of the participle stay as they are there. English uses one auxiliary, had, for every verb, so the choice of avere or essere is real new work.
Imperfetto of avere/essere + participle
| Person | With avere | With essere |
|---|---|---|
| io | avevo parlato | ero andato / andata |
| tu | avevi parlato | eri andato / andata |
| lui / lei / Lei | aveva parlato | era andato / andata |
| noi | avevamo parlato | eravamo andati / andate |
| voi | avevate parlato | eravate andati / andate |
| loro | avevano parlato | erano andati / andate |
parlare (to speak) and andare (to go)
English participles never change, but after essere the Italian participle follows the gender and number of the subject: Anna era arrivata, not Anna era arrivato. After avere it stays on -o: Anna aveva mangiato.
Both in a row
Quando era tornata a casa, aveva già cenato.
When she got home, she had already had dinner.
Non si erano ancora alzati quando ho telefonato.
They had not got up yet when I phoned.
When you need the Trapassato prossimo
The Trapassato prossimo needs a reference point in the past: a second event, a date, a moment in the story. What came before that point goes into the Trapassato.
Before another event
The earlier action goes into the Trapassato, the later one into the Passato prossimo or the Imperfetto. Small words like già, appena and mai usually sit between the auxiliary and the participle.
Quando siamo arrivati, il film era già cominciato.
When we arrived, the film had already started.
Avevo appena chiuso la porta quando ha suonato il telefono.
I had just closed the door when the phone rang.
Non ero mai stato in Sicilia prima di quel viaggio.
I had never been to Sicily before that trip.
The back story as a reason
The Trapassato often explains why something happened, especially after perché (because) and siccome (since).
Ero stanchissima perché avevo lavorato tutta la notte.
I was exhausted because I had been working all night.
Siccome non avevo studiato, l'esame è andato male.
Since I had not studied, the exam went badly.
