Future Perfect Continuous

FORM

Positive: Subject + have/has + been + verb-ing (present participle)
Negative: Subject + have/has + not + been + verb-ing
Question: Have/Has + subject + been + verb-ing?


USAGE

Future perfect continuous is used to talk about:

A) an action that will still in progress at a particular time in the future (or to show a duration before Something in the future). The common time expressions used with future perfect continuous: before, by tomorrow/8 o'clock/next month, until/till; for examples,

• They will have been talking for over an hour by the time Sokha arrives.
• Sokha will have been teaching at PUC for 3 years by the time he leaves for Australia.
• How long will you have been studying when you graduate?
• A: When you finish the course, will you have been living in France for over a year?
  B: No, I will not have been living here that long.

B) cause of something in the future; for examples,

• They might be tired when we see them because they will have been working very hard.
• He’ll be jet lag when he gets home because he will have been flying for over six hours.