for since ago

for and since

We use for and since to say how long:

Unit 18. for since ago


four days
an hour
a week
a month
five years

ten minutes
two hours
three weeks
six months
a long time

We use since + the start of the period ( Monday/ 9 o`clock etc.):

Unit 18. for since ago


9 o`clock
24 July

10 October
I got up

- Barry has been in Canada since January. (= from January to now)
- Barry has been in Canada for six months. ( not since six months)
- I`ve known her since 1980. (= from 1980 to now)
- I`ve known her for a long time. ( not since a long time)
ago = before now:

- Susan started her new job two weeks ago. (= two weeks before now)
- "When did Tom go out?" " Ten minutes ago." (= ten minutes before now)
- I had dinner an hour ago. (= an hour before now)
- Life was very different a hundred years ago.
We use ago with the Past Simple ( did/ had/ started etc.)
Compare ago and for:
- When did she arrive in London?
- She arrived in London four days ago.
- How long has she been in London?
- She has been in London for four days.