Tense concordance
The temporal mechanism between two verbs is called concordance of tenses when one is syntactically dependent on the other. To make it clear and not to make it too complicated, we only speak of concordance when there is a subordinate proposition.
Je veux qu'il sache.
Je vois qu'il sait.
This phenomenon is not specific to the subjunctive since, as we can see in the example above, it also occurs in the indicative. However, the subjunctive has a great characteristic of the tenses: a reduced system of concordance.
The classic system of tense concordance
In the following table, two parameters are taken into account: the timing of the main event and the chronological relationship between the subordinate and the main event.
| Tense of principal | Subordinate present or future | Subordinate past |
|---|---|---|
| Present or future je doute |
Subjunctive present qu'il parte |
Subjunctive past qu'il soit parti |
| Past or conditional je doutais |
Subjunctif imperfect qu'il partît |
Subjunctif pluperfect qu'il fût parti |
Reduced tense concordance system
However, for the subjunctive, a reduced form of tense concordance is used orally and often in writing. Only the chronological relationship between the principal and the subordinate is taken into account. This reduced form is not valid for the indicative.
| Tense of principal | Subordinate present or future | Subordinate past |
|---|---|---|
| All tenses je doute |
Subjunctive present qu'il parte |
Subjunctive past qu'il soit parti |