The Future Perfect Progressive

FORM: will + has / have + been + verb+ing

The future perfect progressive emphasizes the duration of an activity that will be in progress before another time or event in the future.

I will have been studying for 20 years by the time I get my Doctor’s degree.
I will have been walking for 10 hours by the time we arrive back at the military base.

Statement

{ I – You – We – They – He – She – It } will have been eating for two hours before Aisha arrives.

Negative

{ I – You – We – They – He – She – It } will not have been eating for two hours by the time Aisha arrives.

Question

Won’t { I – you – we – they – he – she – it } have been eating for two hours by the time Amy arrives?

Short Answer

Yes, { I – you – we – they – he – she – it } will. / No, { I – you – we – they – he – she – it } won’t.