B1-B2 grammar reference
Future Perfect
Use the future perfect to look back from a future reference point and say that an event will already be complete by then.
Form at a glance
Form: subject + will have + past participle
When to use it
- Completion by a deadline:
We will have finished by Friday.
- A total achieved by a future point:
By June, she will have completed ten modules.
- A prediction about a completed event:
They will have arrived by now.
Sentence patterns
| Form | Pattern | Example |
|---|---|---|
| Affirmative | S + will have + past participle | He will have left by noon. |
| Negative | S + will not have + past participle | We won't have saved enough. |
| Question | Will + S + have + past participle? | Will you have finished by six? |
| Deadline | by + future time | By May, I will have graduated. |
Compare the meaning
Future perfect
Complete before a future point: At six, I will have cooked dinner.
Future progressive
In progress at a future point: At six, I will be cooking dinner.
Common mistakes
- Use a past participle:
will have written
, notwill have wrote.
- By Friday means no later than Friday; until Friday describes continuation up to Friday.
- Make the future reference point clear so the relationship is easy to understand.
Nuance and natural usage
They will have arrived by now
can express a confident deduction about the present, not a literal future event.- The tense is useful for deadlines and forecasts but may sound unnecessarily formal when a simpler sequence is already clear.