We use for and since to say how long something has been happening.
We use for + a period of time (two hours, six weeks etc.):
- I've been waiting for two hours.
for: two hours, 20 minutes, a long time, six months, a week, ages, five days, 50 years, years - 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 (8 o'clock, Monday, 1999 etc.):
- I've been waiting since 8 o'clock.
since: 8 o'clock, April, lunchtime, Monday, 2001, we arrived, 12 May, Christmas, I got up - Sally has been working here since April. (= from April until now)
- I haven't seen Tom since Monday.
|
It is possible to leave out
for (but not usually in negative sentences):
- They've been married (for) ten years. (with or without for)
- They haven't had a holiday for ten years. (you must use for)
We do
not use
for +
all ... (
all day /
all my life etc.):
- I've lived here all my life. (not for all my life)
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)
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 Carol 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.
12.1 Write for or since.
12.2 Write questions with how long and when.
12.3 Read the situations and complete the sentences.
12.4 Write B's sentences using the words in brackets.
