slug: future-perfect-continuous title: Future Perfect Continuous group: tenses order: 12 summary: The duration of an ongoing action up to a specific future point. formula: S + will have been + V-ing
When to use it
Future perfect continuous emphasises how long an activity will have been going on by a future moment. It combines the "completed by a deadline" idea of future perfect with the "ongoing duration" idea of continuous aspect.
By December, I will have been learning English for five years.
The focus is on the length of time (five years), not on whether the studying is fully completed.
Form
| Subject | Affirmative | Negative | Question |
|---|---|---|---|
| I / You / He / She / It / We / They | will have been working | will not have been working | will you have been working? |
will have been is fixed for all subjects. The main verb always takes the -ing form.
Examples
- Next month they will have been living here for ten years.
- By the time the race ends, she will have been running for over three hours.
- Will you have been waiting long when I arrive?
Common mistakes
- Using stative verbs with this tense: "He will have been knowing her for years" is wrong — use future perfect: "He will have known her for years".
- Confusing it with future perfect: future perfect stresses a completed action ("I will have finished"); future perfect continuous stresses ongoing duration ("I will have been finishing" — rarely used, since finish describes a single completion).