Three more common prepositions used with time expressions are for, during and while. Let’s look at how we can use them correctly in our conversations.
For is used to talk about how long something happens. It is always used with periods of time. For example:
◆ I was studying English for three hours.
◆ The photocopier has been broken for a long time.
We can also use for with negative sentences. This shows how much time has passed since we did something, or how much time will pass before we do something.
◆ I have not slept for three days. (= The last time I slept was three days ago.)
◆ I’m not going to eat any sweets for two weeks. (= The next time I eat sweets will be two weeks from now.)
During is used to show when something happens. During is always followed by a noun. For example:
◆ I am going to get a job during my summer vacation.
◆ Please don’t look at your cellphone during the movie.