When will you have collected enough money?
I am talking about the time in future when you have collected enough money...
I guess future perfect should be used here.
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
It's a good usage of the Future Perfect. You can check yourself by making it a declarative sentence:
We use the future perfect to say that something will be finished by or at a particular time in the future.