Future Perfect
Learn how to form the future perfect, and how it shows an action already completed by a specific point in the future.
Looking back from a future point
The future perfect views a future moment as if it has already happened.
The future perfect shows that an action will already be completed by a specific point in the future. It is formed with will have, plus the past participle.
In She will have finished the report by five., will have finished looks ahead to five o’clock and treats the report as already complete by that moment.
This lesson covers how the future perfect is formed and the situations it describes.
Before you begin
This is one of four topics on future tenses.
This lesson focuses on the future perfect specifically. Future tenses as a whole includes three other topics, each covered in its own lesson.
If you would like an overview of future tenses in general, begin with the Future Tenses page.
The central idea
The future perfect adds a deadline the future simple does not have.
Compare a future simple sentence with a future perfect sentence describing a related idea.
01
Future simple
She will finish the report.
02
Future perfect
She will have finished the report by five.
The useful question is: is a specific future deadline being named?
The first sentence simply states a future action, with no deadline attached. The second names five o’clock as the point by which the action will already be complete.
Forming the future perfect
Will have, plus the past participle, for every subject.
I will have finished. She will have finished. They will have finished.
As with the future simple, this form stays the same regardless of the subject. The past participle used here follows the same rules covered in the Past Participle lesson, including irregular forms.
What the future perfect describes
Two related situations call for this tense.
Completion by a specific deadline
She will have finished the report by five.
Completion before another future event
They will have left before you arrive.
Note that the present simple, arrive, follows before here, following the same pattern used in other future time clauses.
By and by the time
Both point to a deadline, in slightly different ways.
by + a specific time → by five, by next Monday, by the end of the month
by the time + a clause → by the time you arrive, by the time the movie starts
A useful decision guide
Ask whether a future deadline is actually part of the sentence.
01
Is a specific future deadline named?
If not, the future simple may fit better instead.
02
Will the action be complete by that point, or still ongoing?
The future perfect fits a completed action, not one still in progress.
03
Is the main verb regular or irregular?
Confirm the correct past participle either way.
04
Does a time clause follow before or by the time?
Use the present simple in that clause, not will.
Common mistakes
A missing have or the wrong participle are the most frequent slips.
Have is not left out between will and the past participle.
Not: She will finished the report by five.
Correct: She will have finished the report by five.
An irregular past participle is not replaced with the past form.
Not: They will have went by then.
Correct: They will have gone by then.
The future perfect is not used without any sense of a deadline.
Not: She will have worked tomorrow.
Correct: She will work tomorrow.
Without a deadline in view, the future simple is usually the more natural choice.
Check your understanding
Which sentence correctly completes each idea?
Choose the correct answer for each sentence.
By the time we arrive, they __________ dinner.
✅ Exactly! “Have” belongs between “will” and the past participle.
❎ Not quite. Is “have” missing here?
What word is missing between “will” and “eaten”?
She __________ home by the time you call.
✅ Exactly! “Gone” is the past participle needed here, not “went”.
❎ Not quite. “Went” is the past form, not the past participle.
Compare this to “has gone” in the present perfect.
Which sentence is more natural, with no deadline mentioned at all?
✅ Exactly! Without a deadline in view, the future simple fits better.
❎ Not quite. Is there a clear deadline mentioned in this sentence?
Is a specific point in the future being named here?
Choose the best explanation
Select the sentence that explains the mistake correctly.
Why is “She will finished the report by five.” not correctly formed?
✅ Exactly! “Will have finished” is the complete, correct form.
❎ Not quite. Focus on what sits between “will” and “finished”.
Why is “They will have went by then.” not correctly formed?
✅ Exactly! “Gone” correctly completes the future perfect here.
❎ Not quite. “Then” correctly refers to the earlier time point in this sentence.
Quick review
The future perfect treats a future moment as if it has already arrived.
The future perfect is formed with will have, plus the past participle, unchanged across every subject.
It describes completion by a specific deadline, or completion before another future event.
By and by the time both point to that future deadline.
Without a clear deadline, the future simple usually fits better instead.
Remember
Look for the deadline this action needs to be finished by.
The future perfect only makes sense alongside a specific future point. Finding that point is the clearest way to confirm this tense fits.