Future Perfect and Future Continuous
Lesson 3 of 4 · ~9 minutes

Lesson 3 · Future Perfect and Future Continuous

by or at?

Finished or in progress

By + will have + V3 says the action will already be finished by the moment. At + will be + -ing says it will still be in progress at that moment. And will be + -ing can also sound neutral — just a fact of the schedule, with no sense of a decision.

by (finished) or at (in progress)

  • byBy 8, I will have cooked dinner — dinner is ready by eight
  • atAt 8, I will be cooking dinner — at eight I'll be in the middle of cooking

Signal

by + a moment
at + a moment

Form

will have + V3
will be + -ing

Meaning

finished before that moment
in progress at exactly that moment
Signal
Form
Meaning
by + a moment
will have + V3
finished before that moment
at + a moment
will be + -ing
in progress at exactly that moment

By 8, I will have cooked dinner; at 8, I will be washing up.

By the time you land, we will have left the airport.

I'll be seeing him tomorrow anyway, so I can ask him then.

Don't worry about a lift — I'll be passing your house anyway.

Where people usually slip

In this sense, will be + -ing is not a decision made on the spot — it's something already settled: I'll be seeing him tomorrow anyway sounds more neutral than I'll see him tomorrow (which can sound like a decision made right now).

Compare will for an on-the-spot decision: I'll call him (just decided) — a completely different shade.

In short

  • bywill have + V3 — already finished
  • atwill be + -ing — in progress
  • neutral planwill be + -ing with no sense of a decision
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