The past future expresses an action that will be completed in the future before another action itself in the future. We also speak of previous future tense. It is found both in subordinate propositions to express an action that will be completed before the second one and in independent propositions to express an action that will be completed at that time.
Le train sera déjà parti quand tu arriveras.
Dans deux ans, les travaux seront terminés.
To be able to form the past future, it is necessary to know how to conjugate the auxiliaries "avoir" and "être" in the simple future and to know how to form the past participle. The main difficulty of the past future comes from the agreements with the past participle.
Here is an example of a verb conjugated in the past future tense with auxiliaries "avoir" and "être":
Subject | Auxiliary (avoir) | Past participle (finir) |
---|---|---|
J' | aurai | fini |
Tu | auras | fini |
Il | aura | fini |
Nous | aurons | fini |
Vous | aurez | fini |
Ils | auront | fini |
Subject | Auxiliary (être) | Past participle (venir) |
---|---|---|
Je | serai | venu |
Tu | seras | venu |
Il | sera | venu |
Nous | serons | venus |
Vous | serez | venus |
Ils | seront | venus |