We use for + a period of time to say how long something goes on:
example:
- I've lived in this apartment for
seven years.
- Are they going away for
the week-end?
DURING
We use during + noun to say when something happen. (not how long)
example:
- My sister fell asleep during
the film.
- We'll phone you some time during
the afternoon.
WHILE
We use while + subject + verb
example:
- I saw Jim while I
was waiting for the bus.
- While you were out, there was a phone call for you.
