The future continuous (will be doing) describes an action in progress at a moment in the future. The future perfect (will have done) describes an action that will be complete before a future moment. Together they help you talk precisely about schedules, deadlines and plans.
The pattern
This time tomorrow, I'll be flying to Denver.
By Friday, we'll have finished the audit.
In June, I'll have been working here for ten years.
01Future continuous: in progress later
Use will be + -ing for an action that will be in progress at a certain future time. It also works for things that will happen anyway, as part of a normal schedule. In questions, it is a polite way to ask about plans: "Will you be joining us?" sounds less pushy than "Will you join us?"
- At 3:00, I'll be meeting with the Dallas team.
- I'll be driving past Target anyway, so I can grab it.
- Will you be needing a receipt?
02Future perfect: done before a moment
Use will have + past participle for an action that will be finished before a future time. It often comes with by, by the time, before and in two weeks. After by the time, when and before, use the present simple, not will. The future perfect can also make a confident guess about now: "They'll have landed by now."
- By the time you read this, I'll have left the office.
- The contractor will have fixed the roof before it gets cold.
- It's 6:00, so she'll have gotten home by now.
03Choosing the right form
Use will have been + -ing to measure how long something will have continued up to a future point. Stative verbs such as know, own and believe do not take continuous forms, so say "I'll have known her for ten years," not "I'll have been knowing her."
| Meaning | Form | Example |
|---|---|---|
| In progress at a future moment | will be + -ing | At 8 p.m., we'll be having dinner. |
| Finished before a future moment | will have + past participle | By 8 p.m., we'll have eaten. |
| Length of time up to a future moment | will have been + -ing | By 8 p.m., we'll have been driving for six hours. |
| Polite question about plans | will you be + -ing | Will you be staying for the reception? |
04Common mistakes
By the time you will arrive, we'll have left.
By the time you arrive, we'll have left.
After by the time, when and before, use the present simple for the future.
At noon tomorrow, I'll sit in a meeting.
At noon tomorrow, I'll be sitting in a meeting.
An action in progress at a future moment needs will be + -ing.
In June, I'll have been knowing him for ten years.
In June, I'll have known him for ten years.
Know is a stative verb, so it does not take a continuous form.
I will have finish the slides by noon.
I will have finished the slides by noon.
Will have is always followed by a past participle.