Future perfect

FORM

((+)) Subject + WILL HAVE + past participle (-ed / 3rd column) + objects --> She will have made dinner by nine o'clock.

((-)) Subject + WILL + NOT + HAVE + past participle (-ed / 3rd column) + objects --> She won't have made dinner by nine o'clock.

(won't)

((?)) WILL + subject + HAVE + past participle (-ed / 3rd column) + objects + ? --> Will she have made dinner by nine o'clock?

We use by before a time expression to explain when the specific moment will be --> We'll have eaten by nine o'clock.

We use it to describe actions that:

will have been completed or not at a certain time in the future --> Will you have had dinner before we go out?

I will finish my work at 8.30. (VS) I will have finished my work by 8.30.

PRACTICE