Futur Antérieur – Future Perfect
Definition: French tense
Antérieur means previous, before, so the futur antérieure describes an event or a state in the future occuring before another future event or state.
You will have finished your homework when I arrive
“When I arrive”, even if in English it is the present tense, describes a futur event and just before it, you will have finished your homework, so the first part in blue needs the future perfect or futur antérieur.
You get it with the future simple of the auxiliary verb (to have) and the past participle (finished)
In French: Exactly the same thing
You get it with the future simple of the auxiliary verb and the past participle (in French, there are two auxiliary verbs: avoir, être)
I will have finished: j’aurai fini
You will have finished: tu auras fini
He, She wil have finished: il, elle aura fini
We will have finished: nous aurons fini
You will have finished: vous aurez fini
They will have finished: ils, elles auront fini
I will have gone: je serai allé(e)
You will have gone: tu seras allé(e)
He, She will have gone:: il, elle sera allé(e)
We will have gone: nous serons allés(es)
You will have gone: vous serez allés(es)
they will have gone: ils, elles seront allés(es)
With the verb to be, you must agree the past participle with the subject
so now, we can translate the sentence above:
Tu auras fini tes devoirs quand j’arriverai
As you can see, in French after “when” you can use the future tense, it is the same thing for the following expressions:
Une fois que: once,
Lorsque: once, when,
Dès que, aussitôt que: as soon as
Once I have arrived, you will leave
2 events in the Future but the first one takes place before the second, you don’t need the future perfect in English, but in French, you need it after once in the future: Une fois que je serai arrivé, tu partiras (je serai arrivé: futur antérieur).
You will come as soon as you have finished
For the same reason, you need the future perfect after “as soon as”: tu viendras dès que j’aurai fini.
If you have the future perfect in English, you will have it in French too
Also after expressions like when, once, as soon as…