Form of the future perfect simple:
Affirmative
Negative
Interrogative
NOTE: Contraction (short form)
I will have finished = I'll have finished
I will not have finished = I won't have finished
Examples:
Use of the simple future simple:
The Future Perfect shows that something will occur before:
Examples:
Form of the simple future continuous:
Affirmative
I will have been teaching.
Negative
I will not/won't have been teaching.
Interrogative
will you have been teaching?
NOTE:
Examples:
It is used to show that an action will continue up until a particular event or time in the future. "For five minutes," and "for two weeks," are all durations which can be used with the Future Perfect Continuous.
Examples: