Future continuous & future perfect

Rules

• Rule 1: will be + -ing = in progress in the future

  Use will be + verb-ing for actions that will still be going on at a particular future moment. Clues: this time tomorrow, at 10 a.m. on Monday, this time next week. It's also a polite way to ask about plans: *Will you be using …?*

  Pattern: subject + will be + verb-ing

  Example: At 3 p.m. tomorrow, we will be visiting the science museum.

  Example: Will you be using the printer this afternoon?

• Rule 2: will have + V3 = finished by then

  Use will have + V3 for actions that will be complete before a future time. The strongest clue is by: by Friday, by 2050, by the time … It fits when there's a result such as a number or “all” (six novels, all the tickets).

  Pattern: subject + will have + V3

  Example: By the end of the term, we will have read six novels.

  Example: By the time you wake up, I will have left for the airport.

• Rule 3: will have been + -ing = how long

  Use will have been + verb-ing to stress how long an action will have continued up to a future time, usually with for + period. (With verbs like live, work, study, *will have lived for ten years* is also heard, but the -ing form is the most natural way to stress duration.)

  Pattern: subject + will have been + verb-ing (+ for + period)

  Example: By July, my aunt will have been working at the hospital for ten years.

  Example: At 6 o'clock, we will have been driving for five hours.

• Rule 4: State verbs and time clauses

  State verbs like be, know, have (own) don't take -ing; for duration we still use will have + V3: *will have known, will have been*. Also, when, by the time, before clauses don't take will; they use the present simple.

  Pattern: By the time + present simple, … will have + V3

  Example: Next year, we will have known each other for ten years.

  Example: By the time the guests arrive, the soup will have cooled down.

Common mistakes

• By Friday, I will finish the book. → By Friday, I will have finished the book.

  by + future time → completion: will have + V3.

• This time tomorrow, I will lie on the beach. → This time tomorrow, I will be lying on the beach.

  In progress at that moment → will be + -ing.

• By the time you will arrive, we will have eaten. → By the time you arrive, we will have eaten.

  No will in the time clause; use the present simple.