The Italian past perfect subjunctive (congiuntivo trapassato) is a verbal form generally used to describe a fact considered not real or not objective, and distinguished by temporal anteriority with respect to an event that took place in the past (Io credevo che a mezzanotte tutti fossero arrivati da parecchio).

The past perfect subjunctive tense can also used in the hypothetical period of unreality when referencing the past (Se avessimo fatto attenzione, avremmo potuto evitare l'errore).


Forming the Italian Past Perfect Subjunctive Tense
The Italian past perfect subjunctive tense (congiuntivo trapassato) is a compound tense (tempo composto), formed with the appropriate imperfect subjunctive conjugated form of the auxiliary verb essere or avere and the past participle of the verb at issue.

CONJUGATING ITALIAN VERBS IN THE PAST PERFECT SUBJUNCTIVE TENSE

	verbs conjugated with the auxiliary verb AVERE; for example, PARLARE	verbs conjugated with the auxiliary verb ESSERE; for example, ANDARE
che io	avessi parlato	fossi andato/a
che tu	avessi parlato	fossi andato/a
che lui, lei, Lei	avesse parlato	fosse andato/a
che noi	avessimo parlato	fossimo andati/e
che voi	aveste parlato	foste andati/e
che loro, Loro	avessero parlato	fossero andati/e

Use of the Past Perfect Subjunctive Tense in the Subordinate Clause
The past perfect subjunctive tense is one of the most complex verbal forms in Italian, given that it simultaneously indicates temporal anteriority with respect to a past moment and, at the same time, some form of unreality.

The verb form is utilized according to the rules of tense agreement and is usually used in the subordinate clause introduced by past tense forms of verbs such as credere, pensare, sperare, or supporre. In these instances, it has the characteristic of indicating anteriority with respect to the time indicated by the forms of these verbs:

• Ho creduto che ormai i pacchi fossero arrivati.

• Pensai che lì fosse piovuto.

• Speravo proprio che Giada avesse sostenuto l'esame.

• Non avevo pensato che tu avessi finito.

The use of the past perfect subjunctive in a subordinate clause, backed by a primary clause in the present indicative, is uncommon, but certainly appropriate when it is possible to imagine a spoken course of action already completed in the past (Penso che all'età di sedici anni mio nonno avesse già imparato l'inglese).

The past perfect subjunctive tense can also express a desire, wish, or longing in certain grammatical constructs introduced by verbs with volitional meaning (such as volere and preferire), provided they are conjugated in the conditional:

• Vorrei tanto che tu avessi finito.

In this case, the subjunctive loses its basic meaning of past perfect, i.e., 'past of the past'; in fact, its function is to indicate the completeness or the simple temporal anteriority of an event set in a present imaginary, unreal world.

The past perfect subjunctive also takes the place of the past perfect indicative in subordinate clauses introduced by conjunctions such as senza che, prima che, nonostante, malgrado, a meno che, a condizione che:

• Io ero partito senza che tu avessi potuto salutarmi.

• Rocco aveva paura dell'esame malgrado avesse studiato parecchio.

• Ti pregai di iniziare quel lavoro, a meno che tu non l'avessi già fatto.

• Si accettavano tutti i cani, a condizione che fossero stati vaccinati almeno un mese prima del loro arrivo.

Unlike the simple tenses of this mode, the past perfect subjunctive does not lend itself well to use in ending clauses (introduced by perché or affinché), nor in sequential phrases (introduced by in modo che).

One of the main uses of the past perfect subjunctive is encountered in the secondary phrase of the hypothetical period of impossibility with reference to the past (as an antecedent):

• Se tu mi avessi lasciato, ieri non avrei saputo che cosa fare.

In this case, the past perfect subjunctive indicates the condition necessary for the event to take place. The conditional clause may be in the present perfect conditional tense but, depending on the temporal constellation of events, may also be in the present conditional:

• Se tu ieri non mi avessi aiutato adesso non saprei che cosa fare.

In the hypothetical period, the function of the past perfect subjunctive tense is not to indicate anteriority with respect to a past time, but rather, to indicate an imaginary, unreal past.

Use of the Past Perfect Subjunctive Tense in the Primary Clause
The use of the past perfect subjunctive tense in the primary clause is uncommon. The past perfect sometimes indicates a doubt framed within a question:

• Non sentivo nessuna voce e mi guardai intorno: che Luciana mi avesse lasciato solo?

In the given example, the function of the past perfect subjunctive is to express an anteriority (or completed aspect) with respect to the past indicated in context with the statement.

More often, when used in the primary clause, the past perfect subjunctive indicates a desire:

• Ah, avessi giocato quei numeri al lotto!

In this case, the time function of the past perfect subjunctive is not to express the 'past of the past': it is limited to indicating that the desire would come to fruition only in the world of an imaginary past. The example is similar in structure to a subordinate clause with the omission of the primary clause (Come sarebbe bello se avessi giocato quei numeri).