For the same reasons as the ones seen in the lesson about present subjunctive, when the first part of the sentence (the part before “que”) expresses a will, a wish, an obligation or a doubt.
It looks like the “Passé Composé”, because it needs an auxiliary verb following with a past participle, the difference is that the auxiliary verb is in subjunctive mood, so you need to know the subjunctive forms of the two auxiliary verbs in French: avoir and être.
Passé Composé: Tu es venu (you came or you have come)
Subjonctif Passé: Que tu sois venu
Passé Composé: Il a mangé
Subjonctif Passé: Qu’il ait mangé
the structure of the sentence is like this: First Part QUE Second Part
If the first part and the second part take place at the same time, we use the present subjunctive to translate the second part.
If the second part takes place before the first one, we use the past subjunctive to translate it.
I am afraid he is coming: j’ai peur qu’il vienne (present)
I am afraid he came: j’ai peur qu’il soit venu (past)
I was afraid that he came: j’ai eu peur qu’il vienne (present)
I was afraid he had come: j’ai eu peur qu’il soit venu (past)
I am happy that he is leaving: Je suis heureux qu’il parte
I am happy he left: je suis heureux qu’il soit parti
I was happy he left: J’étais heureux qu’il parte
I was happy he had left: j’étais heureux qu’il soit parti
(the answer is on the video)
I don’t think he is coming
I don’t think he came
I want him to arrive on time at the station
I wanted him to arrive on time at the station
I wanted him to have arrived on time at the station