Future Perfect Continuous
Learn how to form the future perfect continuous, and how it emphasises duration by a specific point in the future.
Duration up to a future point
This tense keeps the focus on how long something will have continued.
The future perfect continuous emphasises how long an action will have been continuing by a specific point in the future. It is formed with will have been, plus the -ing form.
In By June, she will have been working here for a decade., will have been working emphasises the length of time this job will have continued by June, rather than simply stating that she works there.
This lesson covers how the future perfect continuous is formed, and how it differs from the future perfect.
Before you begin
This is one of four topics on future tenses.
This lesson focuses on the future perfect continuous 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
Duration and completion are two different things to emphasise.
Compare the future perfect continuous with the future perfect, describing related but distinct ideas.
01
Future perfect continuous
By June, she will have been working here for a decade.
02
Future perfect
By June, she will have completed her tenth year here.
The useful question is: is duration or completion the point of this sentence?
The first sentence emphasises the length of time she will have worked there. The second emphasises the completed milestone itself.
Forming the future perfect continuous
Will have been, plus the -ing form, for every subject.
I will have been working. She will have been working. They will have been working.
This form stays the same regardless of the subject, just as the other future tenses do.
What the future perfect continuous describes
The duration of an action leading up to a future point.
By the end of this year, they will have been living here for five years.
This tense is often used to highlight a milestone in an ongoing situation, showing how long it will have continued once a particular future point arrives.
For and by
These two often appear together in the same sentence.
for + a length of time → for a decade, for five years, for six months
by + a future point → by June, by the end of the year, by next Monday
Example
By June, she will have been working here for a decade.
A useful decision guide
Ask whether duration or completion is the point, and check for stative verbs.
01
Is the length of time the main point?
If so, the future perfect continuous usually fits.
02
Is a completed milestone the main point instead?
If so, the future perfect usually fits better.
03
Is the verb a stative verb?
If so, avoid the continuous form here as well.
04
Are both been and the -ing form present?
Both pieces are required to complete this tense.
Common mistakes
A missing been is the most frequent slip.
Been is not left out of this tense.
Not: By June, she will have working here for a decade.
Correct: By June, she will have been working here for a decade.
A stative verb is not put into this continuous form.
Not: By then, I will have been knowing him for years.
Correct: By then, I will have known him for years.
For marks a duration, not a starting point.
Not: She will have been working here for 2016.
Correct: She will have been working here since 2016.
Check your understanding
Which sentence is correctly formed?
Choose the correct answer for each pair.
Which sentence is correctly formed?
✅ Exactly! “Been” is required in this tense.
❎ Not quite. Is “been” missing here?
Compare this to “has been working” in the present perfect continuous.
Which sentence is correctly formed?
✅ Exactly! “Know” is a stative verb and avoids the continuous form.
❎ Not quite. Does “know” describe an action, or a state?
Compare this to “want” and “believe”.
By December, she will have been studying English __________ two years.
✅ Exactly! “Two years” is a length of time, so “for” is correct.
❎ Not quite. Is “two years” a starting point, or a duration?
Compare this to “since 2016” versus “for two years”.
Choose the best explanation
Select the sentence that explains the choice correctly.
Why might “By June, she will have been working here for a decade.” be chosen over “By June, she will have completed her tenth year here.”?
✅ Exactly! Both sentences are correct; the choice depends on what the speaker wants to emphasise.
❎ Not quite. Both sentences are grammatically correct here.
Why is “By June, she will have working here for a decade.” not correctly formed?
✅ Exactly! “Will have been working” is the complete, correct form.
❎ Not quite. Focus on what sits between “have” and “working”.
Quick review
The future perfect continuous keeps duration at the center of the sentence.
The future perfect continuous is formed with will have been, plus the -ing form, unchanged across every subject.
It emphasises duration leading up to a specific future point.
The future perfect, in contrast, often emphasises a completed milestone.
Stative verbs avoid this continuous form, just as they do in the other continuous tenses.
Remember
Ask whether duration is the point, or a milestone is.
When how long something will have continued matters more than a specific completed achievement, the future perfect continuous is usually the better fit.