Future Perfect Continuous tense is used to express situations that will last for a specified period of time at a definite moment in the future. We also use this tense to express certainty about the cause of some future situation.
Structure of Future Perfect Continuous Tense
Positive: Subject + will have been + Verb-ing
Negative: Subject + will not have been + Verb-ing
Question: Will + Subject + have been + Verb-ing
- You will have been waiting for more than two hours when her plane finally arrives.
- Will you have been waiting for more than two hours when her plane finally arrives?
- You will not have been waiting for more than two hours when her plane finally arrives.
More examples:
- They will have been eating for over 15 minutes by the time Mary arrives.
- Thomas will have been studying at the university for more than a year by the time he leaves for Asia.
- How long will you have been studying when you graduate?
- A: When you finish your English course, will you have been living in New Zealand for over a year?
B: No, I will not have been living here that long.
How to Use
1. Duration of an action: Future Perfect Continuous is used to express situations that will last for a specified period of time at a definite moment in the future. It is important that we expect these situations to last longer.
- Before they come, we will have been cleaning the house for 5 hours.
- By the next year, Ben and his wife will have been living together for 50 years.
2. Cause of an action: We also use this tense when they want to express certainty about the cause of some future situation.
- By this time, he will have been working for 12 hours, so he will be very tired.
- We will be making a rest stop in half an hour, because you will have been driving the car for 6 hours by then.
Using questions beginning with “how long” are more common with Future Perfect Continuous.
- How long will you have been learning German this year?
- How long will you have been trying to get your driving license this week? I hope you’ll finally make it!