FOR and SINCE WHEN … ? and HOW LONG … ?

Learn and practise the model for and since when … ? and how long … ?

A We use for and since to say how long something has been happening.

We use for + a period of time:

  • We’ve been waiting for two hours.

for + period of time

  • Sally has been working here for six months. (not since six months)
  • I haven’t seen Tom for three days.

We use since + the start of a period:

  • We’ve been waiting since 8 o’clock.

since + period of time

  • Sally has been working here since April. (= from April until now)
  • I haven’t seen Tom since Monday.
  • B We often leave out for (but not usually in negative sentences):

    • They’ve been married for ten years. or They’ve been married ten years.
    • They haven’t had a holiday for ten years. (you need for)

    You can use in instead of for in negative sentences (I haven’t … etc.):

    • They haven’t had a holiday in ten years. (= for ten years)

    We do not use for + all … (all day / all my life etc.):

    • I’ve lived here all my life. (not for all my life)
    C Compare when … ? (+ past simple) and how long … ? (+ present perfect):

    a: When did it start raining?
    b: It started raining an hour ago / at 1 o’clock.

    a: How long has it been raining?
    b: It’s been raining for an hour / since 1 o’clock.

    a: When did Joe and Kate first meet?
    b: They first met a long time ago / when they were at school.

    a: How long have they known each other?
    b: They’ve known each other for a long time / since they were at school.

    C We say:

    since + period of time

    • It’s two years since I last saw Joe. or It’s been two years since
      (= I haven’t seen Joe for two years)
    • It’s ages since we went to the cinema. or It’s been ages since
      (= We haven’t been to the cinema for ages)
    • How long is it since Mrs Hill died? or How long has it been since
      (= when did she die?)