Questions & Answers about Liberamos al prisionero.
It tells you the subject is we.
Liberamos is the first-person plural form of liberar. In other words, the verb ending -amos shows that the subject is nosotros / nosotras.
So the full idea is:
- (Nosotros) liberamos al prisionero = We free / freed the prisoner
Spanish often leaves the subject pronoun out because the verb ending already gives that information.
It can be either one.
With -ar verbs, the nosotros form is the same in:
- the present indicative: we free / we release
- the preterite: we freed / we released
So liberamos can mean either:
- we free / are freeing
- we freed / released
Only the context tells you which one is intended.