Future Perfect Tense.

Future perfect tense refers to the happening of task or activity before the time in which the task or activity is occuring in the future time.For example;-
I will have not seen him before.

Positive tense;-
Sub + will/shall+ have + verb 3rd form + obj.
Negative tense;-
Sub + will/shall+have not+ verb 3rd form + obj.
Interrogative tense;-
Will/shall +sub + have+verb 3rd form +obj +?