We use the FUTURE PERFECT to indicate that an action will have been completed (finished or "perfected") by a certain time in the future.
This tense is formed with "WILL" + "HAVE" + the past participle of the verb (which can be either regular or irregular in form).
Example: I will have spent all my money by this time next year.
| AFFIRMATIVE | NEGATIVE | QUESTION |
|---|---|---|
| I WILL HAVE WORKED | I WON'T HAVE WORKED | WILL I HAVE WORKED ? |
| YOU WILL HAVE WORKED | YOU WON'T HAVE WORKED | WILL YOU HAVE WORKED ? |
| HE WILL HAVE WORKED | HE WON'T HAVE WORKED | WILL HE HAVE WORKED ? |
| SHE WILL HAVE WORKED | SHE WON'T HAVE WORKED | WILL SHE HAVE WORKED ? |
| IT WILL HAVE WORKED | IT WON'T HAVE WORKED | WILL IT HAVE WORKED ? |
| WE WILL HAVE WORKED | WE WON'T HAVE WORKED | WILL WE HAVE WORKED ? |
| YOU WILL HAVE WORKED | YOU WON'T HAVE WORKED | WILL YOU HAVE WORKED ? |
| THEY WILL HAVE WORKED | THEY WON'T HAVE WORKED | WILL THEY HAVE WORKED ? |
USES:
1. Completion before a specified point in the future.
The first use of this tense is to talk about future actions that will be finished before some specified point in the future.
Before the guests arrive, we will have cleaned up all the rooms.
I read 50 pages a day. If I keep up the pace, I will have read the book by next Saturday.
2. Duration in the Future.
Another use of this tense is to talk about actions will last after a given point in the future.
By next month, I will have known my best friend for 12 years.
3. Certainty About the Near Past.
The last use is to express conviction that something happened in the near past.
The ferry will have left the port by now. We have to look for another way to get to London. (I'm sure the ferry has left)
* Common Time Expressions
Some time expressions are commonly used with the Future Perfect:
- By
- By the time
- Before
- By tomorrow / 12 o'clock / next year
- Until / till