For, During, and While are three of the most common prepositions used in time expressions.
Here are the general rules of using for, during, and while.
|For is used to express how long something or someone has been doing something.
For is used to state a period of time and is usually used with a noun or a pronoun.
|We waited for an hour outside the theatre for you.
Curtis has been riding his bicycle for two hours.
Rosie, my dog, has been barking for a long time.
The traffic has been bad for the last five years.
Formula: (while + subject + verb)
|While is used to represent the length of time an action has been happening.
|While I was playing the piano, my husband was doing the dishes.
|While is used when speaking about two actions happening at the same time. The length of the action is not important.
|While we were eating dinner, the radio was playing.
|While is used with a subject and a verb (while + subject + verb)
|The doorbell rang while we were eating dinner.
Formula: during + noun (pronoun)
|During is used to say when something happens.
|I will be really busy during the next year.
|During is used with a noun/pronoun.
|The children were sleeping during the movie.
The power went out during the snow storm.