In which of the following sentences is the underlined verb in the future perfect tense?

A. She really should begin to pack.
B. They will take the dog to the park with them.
C. Jean's daughter has begun to drive.
D. By that time, he will have been gone for three days.

Question

In which of the following sentences is the underlined verb in the future perfect tense? 
 
     A. She really should begin to pack. 
B. They will take the dog to the park with them. 
C. Jean's daughter has begun to drive. 
D. By that time, he will have been gone for three days.

anonymous · Answer

D is Future Perfect. How? Like this: 
We form the Present Perfect by saying "has done", "have eaten" etc. We form the Future by saying " will" do, "will" eat. 
And we form the Future Perfect by combining the Present Perfect with the Future = I will have done, you will have eaten, she will have been, they will have given, he will have taken etc.