The Italian passive, like the English passive, is a construction which focusses attention on the object of an action (for the passive with si, see section 24.6). The direct object of a transitive verb becomes the subject of the passive. The passive with essere may be used in all tenses and moods, and with modals:

Le innovazioni caravaggesche furono adottate da artisti di molti paesi.

Caravaggio's innovations were adopted by artists in many countries.

Credo che le prenotazioni siano già state chiuse.

I think bookings have already been closed.

Questa proposta potrebbe essere riformulata per la prossima riunione.

This proposal could be reworked for the next meeting.

Passive with venire

The passive may be formed with venire instead of essere to express an action rather than a state. This often avoids the ambiguity of essere + past participle, which may express a passive event, or may describe a state with the participle acting as adjective. Venire may be used as auxiliary only in the simple tenses, indicative and subjunctive, i.e. present, imperfect, passato remoto, future, and conditional, and is most often used with the third person.