Future Perfect Continuous

will have been + present participle, ie. -ing

am/is/are + going to have been + present participle, ie. -ing

Duration Before Something in the Future

They will have been talking for over an hour by the time Kate arrives.

Cause of Something in the Future

Paul will be tired when he gets home because he will have been swimming for over an hour.

1. The two forms of the Future perfect continuous

The Future perfect continuous has two forms.

  • will have been doing
  • be going to have been doing

Unlike Simple Future forms, with the Future Perfect Continuous forms it does not usually matter which form you use.

2. Future Perfect Continuous with "Will"

Form: will have been + present participle, ie. -ing

  • You will have been waiting for more than three hours when his train finally arrives.
  • Will you have been waiting for more than three hours when his train finally arrives?
  • You will not have been waiting for more than three hours when his train finally arrives.

3. Form: Future Perfect Continuous with "Be Going To"

Tvar: am/is/are + going to have been + present participle, ie. -ing -ing

  • You are going to have been waiting for more than three hours when his train finally arrives.
  • Are you going to have been waiting for more than three hours when his train finally arrives?
  • You are not going to have been waiting for more than three hours when his train finally arrives.

4. Duration Before Something in the Future

We use the Future Perfect Continuous to show that something will continue up until a specific event or time in the future. "For 30 minutes," "for three weeks," and "since Monday" are all durations which can be used with the Future Perfect Continuous. It is important to remember the duration stops at or before a reference point in the future.

  • They will have been talking for over an hour by the time Kate arrives.
  • She is going to have been working at that shop for five years when it finally closes.
  • Simona will have been teaching at the school for more than a year by the time she leaves for Japan.
  • How long will you have been studying when you graduate?
  • We are going to have been driving for over 4 days non stop when we get to Paris.
  • A: When you finish your English course, will you have been living in New York for over two years?
  • B: No, I will not have been living here that long.

Notice in the examples above that the reference points are in Simple Present rather than Simple Future. (arrives, closes, leaves etc)

5. Cause of Something in the Future

Using the Future Perfect Continuous before another action in the future is a good way to show cause and effect.

  • Paul will be tired when he gets home because he will have been swimming for over an hour.
  • Jitka’s English will be perfect when she returns to Germany because she is going to have been studying English in London for over two years.

6. Future Continuous vs. Future Perfect Continuous

If you do not include a duration such as "for thirty minutes," "for three weeks" or "since Monday," many English speakers choose to use the Future Continuous rather than the Future Perfect Continuous.
Be careful because this can change the meaning of the sentence. Future Continuous emphasizes interrupted actions, whereas Future Perfect Continuous emphasizes a duration of time before something in the future.
Study the examples below to understand the difference.

  • He will be tired because he will be exercising so intensely.
  • This sentence emphasizes that he will be tired because he will be exercising at that exact moment in the future.
  • He will be tired because he will have been exercising so intensely.
  • This sentence emphasizes that he will be tired because he will have been exercising for a period of time. It is possible that he will still be exercising at that moment OR that he will just have finished.

7. No Future tense with time expressions

Like all future forms, the Future Perfect Continuous cannot be used in clauses beginning with time expressions such as: when, while, before, after, by the time, as soon as, if, unless, etc. Instead of Future Perfect Continuous the Present Perfect Continuous is used. The reason for this is the time expressions already refer to the future so it is not necessary to use “will”

  • You won’t get promoted until you will have been working here as long as Simon. Incorrect
  • You won’t get promoted until you have been working here as long as Simon. Correct

8. The Position of Adverbs

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.

  • You will only have been waiting for a few minutes when his train arrives.
  • Will you only have been waiting for a few minutes when his train arrives?
  • You are only going to have been waiting for a few minutes when his train arrives.
  • Are you only going to have been waiting for a few minutes when his train arrives?

9. Active / Passive

  • The construction company will have been building my new house for over seven months by the time it is finished. Active
  • My new house will have been being built by the construction company for over seven months by the time it is finished. Passive
  • The construction company is going to have been building my new house for over seven months by the time it is finished. Active
  • My new house is going to have been being built by the construction company for over seven months by the time it is finished. Passive

Passive forms of the Future Perfect Continuous are not common.

 

Tests: