Future Perfect Continuous Sentence

Explanation

When I graduate from university, I will have been studying for ten years.

I am studying now. I am going to graduate in the future. I will continue to study until I graduate. The total amount of time I will spend studying is ten years.

By the time Sharon finishes the triathlon, she will have been exercising for four hours.

Sharon will be exercising for four hours continuously. She will be exercising in the future. The total amount of time she will be exercising is four hours.

I was wrong. Michael will not have been driving for eight hours when he arrives. He will have been driving for twelve hours!

Michael will drive for twelve hours continuously. He will be driving in the future. The total amount of time he will be driving is twelve hours.

Is it really true? Will you have been living together for five years this fall?

The people are living together now. In the future (the fall) they will still be living together. The time spent living together will equal five years.