A. USE

1. The Future Perfect tense is used to refer to a non-continuous action which will be completed by a certain time in the future.
Future Perfect, gelecekte belirli bir zamandan önce tamamlanmış olacak eylemleri ifade etmek için future perfect tense kullanılır.

In September, I will have lived in Malatya for four years.
Thomas will have finished the project by Wednesday.

2. By + noun and by the time + sentence are used to express in Future Perfect.
Future Perfect ile by, by the time, before, in a week, when gibi zaman bağlaçları sıklıkla kullanılabilir.

I will have done my homework by the time he comes.
I will have been awake for 24 hours by 12 o'clock.

B. STRUCTURE

Positive Structure:
I
You
He
She will have worked.
It
We
They

Negative Structure:
I
You
He
She will not have worked.
It won't have
We
They

Question structure:
I
You
Will He
Won't She have worked?
It
We
They