In short

The past subjunctive (le subjonctif passé) is the subjunctive’s “completed” tense: aie/sois + past participle. Use it inside a subjunctive trigger when the action is already finished relative to the main verb - Je suis content que tu sois venu (glad you came, i.e. that you have come).

The rule

You already know the present subjunctive and when it is triggered (see Lessons 37-38). The past subjunctive keeps exactly the same triggers - it only changes the time relationship. It is a compound tense built like the passé composé, but with the auxiliary in the present subjunctive.

Choose by anteriority, not by the calendar:

• Present subjunctive = the action is simultaneous with or later than the main verb: Je veux qu’il parte (I want him to leave / to be leaving).
• Past subjunctive = the action is already completed before the main verb: Je suis heureux qu’il soit parti (I am happy that he has left).

aie / sois + past participle

The auxiliary is avoir or être in the present subjunctive, followed by the past participle:

• avoir verbs: que j’aie fini, que tu aies mangé, qu’il ait compris.
• être verbs (movement + all pronominals): que je sois venu(e), que tu sois parti(e), qu’elle soit arrivée.

All the agreement rules of the passé composé still apply (see Lessons 20-21): with être, the participle agrees with the subject (qu’elle soit partie); with avoir, it agrees with a preceding direct object (les lettres que tu aies écrites).

Anteriority in the subjunctive

The subjunctive has no full sequence of tenses in modern French. In everyday speech only two forms are alive: present (non-anterior) and past (anterior). So the trigger clause never “shifts to the past” the way the indicative does - you pick present vs past only by whether the subordinate action is done:

• Je doute qu’il vienne. - I doubt he will come. (not yet done)
• Je doute qu’il soit venu. - I doubt he came. (already done)

The main verb can be present, past, or future - it does not change this choice. J’avais peur qu’il ait oublié (past main verb, still the past subjunctive).

Advanced / literary triggers; subjunctive in superlative and relative clauses

Beyond the core “obligation, emotion, doubt” triggers, B2 adds several patterns that also demand the subjunctive:

• After a superlative or a limiting expression (le seul, le premier, le dernier, l’unique, le meilleur, ne…que), when the relative clause states a subjective judgment: C’est le plus beau film que j’aie jamais vu. C’est la seule personne qui me comprenne.
• In a relative clause expressing a sought or hypothetical quality - the antecedent may not exist: Je cherche un assistant qui sache le russe (any such person, if one exists) vs indicative Je connais un assistant qui sait le russe (a real, known one).
• After certain conjunctions: avant que, jusqu’à ce que, bien que / quoique, pour que / afin que, à condition que, sans que, à moins que, de peur que: Bien qu’il ait tout compris, il n’a rien dit.
• Literary tenses (recognition only): classic and formal writing uses the imparfait du subjonctif and plus-que-parfait du subjonctif (qu’il fût, qu’il eût compris). You will meet them in novels; in speech and normal writing, replace them with the present and past subjunctive.

Forms & patterns

Past subjunctive = present subjunctive of the auxiliary + past participle.

Auxiliaries in the present subjunctive (memorize these two):

Present vs past subjunctive - the anteriority contrast:

Literary tenses (recognize, do not produce):

Examples

Common mistakes

• Je suis content que tu es venu -> que tu sois venu - the trigger forces the subjunctive, so the auxiliary must be sois, not indicative es.
• Je doute qu’il a fini -> qu’il ait fini - after douter que, use the subjunctive auxiliary ait.
• qu’elle soit parti -> qu’elle soit partie - with être, the participle agrees with the subject.
• C’est le plus beau film que j’ai vu -> que j’aie vu - a superlative + relative judgment takes the subjunctive.
• Bien qu’il a compris -> Bien qu’il ait compris - bien que always triggers the subjunctive.
• Je suis content qu’il vienne hier -> qu’il soit venu hier - the action is already completed, so the anterior form (past subjunctive) is required.

Tips

• Build it like the passé composé, then just put the auxiliary in the subjunctive: a mangé -> ait mangé, est venu -> soit venu.
• One question decides present vs past: is the subordinate action already done? Yes -> past subjunctive; no -> present subjunctive.
• The tense of the main verb is irrelevant to the choice - only anteriority matters.
• Keep all passé composé agreement habits: être agrees with the subject, avoir agrees with a preceding direct object.
• Superlatives and le seul / le premier / ne…que plus a relative clause of opinion pull the subjunctive - a very common B2 exam point.
• fût, eût, eût compris are literary: read them, understand them, but write the modern soit / ait / ait compris.