3.4.3. Agreement of tenses with the past subjunctive

The congiuntivo passato is used when the action of the dependent clause took place (or was believed/hoped to take place) before the action of the main verb (the subjunctive trigger). Examples:

Credo che ieri Giulia non abbia votato per il mio partito.

I think Giulia yesterday didn’t vote for my party

Spero che tu non sia andato a casa da solo!

I hope you didn’t go home all alone!