The imperfect of the subjunctive is often seen as a complicated time. However, even if it is no longer used orally, it is alive to the written word especially in its third form singular. The other forms are much more rare. But sometimes a writer or speaker uses one of these forms to raise the level of his/her language and thus obtain a level of language more than sustained. Snobbery or not, it does not prevent that once we know it, the imperfect of the subjunctive is not so complicated as that.
In writing, the imperfect of the subjunctive is used for the concordance of tenses when the principal proposition is in the past. Orally, it is replaced by the present indicative.
The imperfect of the subjunctive is formed from the third person of the singular of the simple past. We then add the endings that are always the same to the three groups: -sse, -sses, -^t (be careful not to forget the circumflex accent), -ssions, -ssiez, -ssent. Note that in the third person singular, we add a circumflex accent.
Je souhaitais qu'il comprît la leçon.
Il fallait qu'il jouât.
Il fallait que je lui rendisse son bien.
There is so little exception in the endings of the imperfect of the subjunctive that it becomes... an exception with "tenir" and "venir". Indeed, we write "que je tinsse" and "que je vinsse" with two "s" in front of a "n". This is not an error, this is only the rule application with the correct ending of the subjunctive imperfect.
Here is the conjugation for some verbs at the subjunctive imperfect:
Person | Aimer | Finir | Tenir |
---|---|---|---|
que je que tu qu'il que nous que vous qu'ils |
aim - a - ss - e aim - a - ss - es aim - â - t aim - a - ss - i - ons aim - a - ss - i - ez aim - a - ss - ent |
fini - ss - e fini - ss - es finî - t fini - ss - i - ons fini - ss - i - ez fini - ss - ent |
t - in - ss - e t - in - ss - es t - în - t t - in - ss - i - ons t - in - ss - i - ez t - in - ss - ent |
Person | Ouvrir | Pouvoir | Venir |
que je que tu qu'il que nous que vous qu'ils |
ouvr - i - ss - e ouvr - i - ss - es ouvr - î - t ouvr - i - ss - i - ons ouvr - i - ss - i - ez ouvr - i - ss - ent |
p - u - ss - e p - u - ss - es p - û - t p - u - ss - i - ons p - u - ss - i - ez p - u - ss - ent |
v - in - ss - e v - in - ss - es v - în - t v - in - ss - i - ons v - in - ss - i - ez v - in - ss - ent |
Il était urgent qu'il changeât ses essuie-glaces. (imparfait du subjonctif)
Lorsqu'il vit qu'ils étaient usés, il changea ses essuie-glaces. (passé simple)