Future perfect: will have + V3

Rules

• Rule 1: will have + past participle

  For an action that will be finished before a future moment, use will have + past participle (V3). will is the same for every subject and is always followed by have (~~will has~~).

  Pattern: Subject + will have + V3 (short form: 'll have)

  Example: She will have left by six.

  Example: We'll have painted the room by Sunday.

• Rule 2: by + time / by the time + present simple

  The future perfect's best friend is by: by Friday, by 2030, by then (no later than that time). After by the time we use the present simple, even though we mean the future. Never put will in the time clause.

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

  Example: By the time you arrive, the movie will have started.

  Example: By the time Dad gets home, we'll have cooked dinner.

• Rule 3: Negatives and questions

  Negative: won't have + V3 (will not have). Question: Will + subject + have + V3? Short answers repeat will / won't.

  Pattern: won't have + V3 · Will + subject + have + V3?

  Example: I won't have finished by five.

  Example: Will you have packed by tonight? — Yes, I will.

• Rule 4: by or until? will be -ing or will have V3?

  by = a deadline (no later than): for actions that will be finished. until = something continues up to that time: I'll wait until six. Don't mix them up: will be + -ing = in progress at a future moment; will have + V3 = finished by that moment. will have been + -ing tells how long something will have been going on (a C1 topic).

  Example: At 7, I'll be having dinner.

  Example: By 8, I'll have had dinner.

Common mistakes

• She will has finished by then. → She will have finished by then.

  After will, always use have.

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

  No will after by the time; use the present simple.

• I will have finish my project by Friday. → I will have finished my project by Friday.

  have is followed by the past participle.