Structure [subject + will have been + -ing verb + object]
The structure is [subject + will have been + ing form + object]
For negative sentences
[ Subject + will not / won’t + have + been + verb (ing)…]
For question sentences
[Will + subject + have + been + verb (ing)…?]
[Won’t + subject + have + been + verb (ing).. ?]
So, as you can see, the future perfect continuous is very similar to the future perfect simple. The main difference is that the future perfect simple normally describes something that will end at a point in the future, while the future perfect continuous will be used to imply that the action will continue in the future.
By next march, we will have been living here for five years.
I’ll have been training you for 5 years by next January.
Won’t they have been managing us for a year, by next year?
My family will have been cooking for an hour by the time we arrive.
When I turn 30, I will have been studying English for 15 years.
Tips: State verbs or non-action words do not work in this tense.
I will have been knowing you for three years. (incorrect)
I will have known you for three years. (correct)
Other verbs like this: know, seem, be, like, love, understand