Imperfect and pluperfect subjunctive

The imperfect subjunctive and pluperfect subjunctive are literary tenses. You'll meet them in classic novels, formal speeches and some fixed expressions. Modern French replaces them with the present and past subjunctive, but at C2 you should recognise them instantly, and the 3rd person singular is still used in elegant writing.

Formation

Take the passé simple (tu form), drop the last letter, add -sse, -sses, -^t, -ssions, -ssiez, -ssent. The 3rd person singular has a circumflex.

• Il fallait qu'il vînt.He had to come.
• Je craignais qu'elle ne fût partie.I was afraid she had left.

When it's used

In classical style, when the main verb is in a past tense, the subjunctive follows it into the past:

• Je voulais qu'il chantât.I wanted him to sing. (modern: qu'il chante)
• Bien qu'il fût tard, il continua.Although it was late, he carried on.

The pluperfect subjunctive as a conditional

In literary French, eût / fût + past participle can replace the past conditional:

• Il eût été préférable de se taire.It would have been better to keep quiet.
• N'eût été sa prudence, il serait mort.Had it not been for his caution, he would have died.

Don't confuse il fut (passé simple, no circumflex) with qu'il fût (subjunctive). The circumflex is the only written difference.

Related: Passé simple, Past subjunctive.