The prepositions ‘for’, ‘during’ and ‘while’ are often used in time expressions.

  • For is followed by a length of time : for one hour.
    It answers the question : How long?
    • I have been standing here for 10 minutes.
    • Tony is going to San Francisco for a week.
    • My parents lived in London for 2 years.
    • Have you been attending English classes for a long time?
  • During is followed by a noun.
    It means ‘throughout the period‘ or ‘in the course of’ an action or event.
    • During the summer I go to the beach as often as possible.
    • Exercises were given to us during the lesson.
    • The bank was robbed during the night.
    • My grandparents often come to stay with us during the winter.
  • While is usually followed by a subject and a verb.
    It means ‘during the time that an action is taking place’.
    • They held hands while they were watching the film.
    • The students took notes while the teacher was speaking.
    • We’ll collect some seashells while we’re walking on the beach.
    • Alex phoned while you were out.

    It is often possible to drop subject + be :

    • I generally listen to music while driving to work.
    • Sam twisted his ankle while playing tennis.
  • While can also be a noun which means ‘a period of time’.
    • I spoke to the neighbour for quite a while yesterday.
    • It’s been a while since I read that book.