This tense describes an action that "will have" happened. It points to a future action that is completed before another point in the future.
The most common use is to show an action that will be finished before another action happens in the future. It sets up a sequence: first this, then that.
Quand tu
auras fini tes devoirs, tu pourras jouer.
(When you have finished your homework, you can play.)
Je t'appellerai
dès que j'
aurai mangé.
(I will call you as soon as I have eaten.)
Après qu'elle
sera arrivée, nous commencerons la réunion.
(After she has arrived, we will start the meeting.)
Nous partirons
une fois que nous
aurons reçu le signal.
(We will leave once we have received the signal.)
Dès qu'il
aura lu le livre, il me le prêtera.
(As soon as he has read the book, he will lend it to me.)
You can also use it to talk about an action that will be completed by a certain time or deadline in the future.
D'ici demain soir, j'
aurai terminé ce projet.
(By tomorrow evening, I will have finished this project.)
Dans une heure, le film
aura commencé.
(In an hour, the movie will have started.)
Elle
aura appris les bases
avant la fin du mois.
(She will have learned the basics before the end of the month.)
À Noël, nous
aurons déménagé.
(By Christmas, we will have moved.)
Sometimes, this tense is used to express a supposition or a strong guess about a past event. It's like saying "must have" or "probably" in English.
Il n'est pas là. Il
aura manqué son bus.
(He isn't here. He must have missed his bus.)
La lumière est allumée. Elle
sera rentrée plus tôt.
(The light is on. She probably got home early.)
Je ne trouve pas mes clés. Je les
aurai laissées dans la voiture.
(I can't find my keys. I must have left them in the car.)
It can be used to look back on the duration of an action from a future point in time. It often talks about an experience or state that will reach a milestone.
En janvier, nous
aurons habité ici pendant dix ans.
(In January, we will have lived here for ten years.)
Bientôt, j'
aurai travaillé ici toute ma vie.
(Soon, I will have worked here my whole life.)
Notice that this tense is often used in a sentence with another future action. The "futur antérieur" marks the first action to be completed.
