Future perfect

The future perfect = will have + past participle (V3), the same for every subject — always will have, even with he / she / it.

💡In fast speech, will have becomes 'll have and the have is very weak, almost “I'll've finished”. When listening, notice the past participle after it (finished, gone, left) — that is the sign of the future perfect.

1. Something that will be finished before (or by) a moment in the future — often with by + a time, by the time + clause, before

• Don't worry — I'll have sent you the file by lunchtime.

• By the time we get to the station, the last train will have left.

• Call me after eight. I won't have finished work before then.

2. Counting a period of time or an amount up to a future moment — will have + V3 + for…

• Next June, Lan will have worked here for five years.

• By the end of this course, you will have learned over 500 new words.

• In December, my parents will have been married for thirty years.

To stress a continuing activity, you can use will have been + -ing (the future perfect continuous): By six, I'll have been driving for ten hours.

3. Guessing that something has probably already happened — about now or the past, not the future

• It's ten o'clock. Mai will have arrived in Hanoi by now.

• You'll have heard the news, I suppose.

💡Don't use the past simple for something that hasn't happened yet (I finished it by Friday). When there is a future moment and the idea is “it will already be done by then”, think of will have + V3. (I'll finish it by Friday is also correct — it simply says what you will do; I'll have finished it by Friday stresses that it will be complete at that moment.)

• by + a time = not later than that time, very common with will have + V3: I'll have finished by Friday.
• by the time + present simple = before…: By the time you wake up, I'll have left (not: will wake up) — see the lesson “Future time clauses”.
• until = continuing up to that time, used with an action that lasts: I'll be working until six (not: I'll have finished until six) — see the lesson “By vs until”.

Will be -ing or will have + V3? At that moment, if the action is in progress → will be -ing; if it is finished → will have + V3.

• At seven, I'll be cooking dinner, so don't call.

  in progress

• By eight, I'll have eaten, so we can talk then.

  finished

• ✗By next week, I will finished the course.

  ✓By next week, I will have finished the course.

  have is missing.

• ✗The party will have finish by then.

  ✓The party will have finished by then.

  After will have, use the V3.

• ✗Nga will has saved enough money by June.

  ✓Nga will have saved enough money by June.

  After will it is always have, even with he / she.

• ✗By the time we will arrive, they will have eaten.

  ✓By the time we arrive, they will have eaten.

  After by the time → present simple.

• ✗I'll have finished the essay until Friday.

  ✓I'll have finished the essay by Friday.

  A deadline → by; until means continuing up to.

• ✗Next year I will work here for six years.

  ✓Next year I will have worked here for six years.

  Counting time up to a future moment → will have + V3.