The Perfect subjunctive or past subjunctive ("congiuntivo passato"), is a "compound tense" (like the "passato prossimo") because it is formed with the present subjunctive of an auxiliary verbs ("essere" or "avere") plus the past participle of a verb.
Whether it requires "essere" or "avere", depends on the verb. If the verb is a transitive verb, it requires the auxiliary "avere". If the verb is intransitive (like most verbs that express movement or state of being) or if the verb is reflexive, it requires the auxiliary "essere".
| Personal Pronoun | Auxiliar "avere" | Past Participle | English |
|---|---|---|---|
io |
abbia |
parlato |
I have spoken, I spoke |
tu |
abbia |
parlato |
you have spoken, you spoke |
lei |
abbia |
parlato |
she has spoken, she spoke |
noi |
abbiamo |
parlato |
we have spoken, we spoke |
voi |
abbiate |
parlato |
you have spoken, you spoke |
loro |
abbiano |
parlato |
they have spoken, they spoke |
| Personal Pronoun | Auxiliar "essere" | Past Participle | English |
|---|---|---|---|
io |
sia |
arrivato |
I have arrived, I arrived |
tu |
sia |
arrivato |
you have arrived, you arrived |
lei |
sia |
arrivata |
she has arrived, she arrived |
noi |
siamo |
arrivati |
we have arrived, we arrived |
voi |
siate |
arrivati |
you have arrived, you arrived |
loro |
siano |
arrivate |
they (f.) have arrived, they arrived |
"Dormire" (to sleep), "rispondere" (to answer), "viaggiare" (to travel), "vivere" (to live) though intransitive require the auxiliary "avere" ("ho dormito, ho risposto, ho viaggiato, ho vissuto...")
Verbs that express movement, like "venire" (to come), "andare" (to go), "uscire" (to go out)... require the auxiliary "essere"
Verbs that express state of being, like "essere" (to be), "stare" (to stay), "rimanere" (to remain), "nascere" (to be born)... require the auxiliary "essere"
Examples: