For and Since

Study the basic to advanced uses of for, since, when…?, and how long…? in English with helpful examples. Learning the use of since and for helps us understand how we need to talk about the time period in English. Talking about when or how long? These phrases or words are used to talk about when and how long something has been happening. Let’s learn the uses of these words and enhance your English conversation skills.

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

For

VS.

Since

We use for + a period of time (two hours, six weeks, etc.):

I’ve been waiting for two hours.

We can use “For” with:

two hours
20 minutes
five days
50 years
ages
a week
six months

We use since + the start of a period (8 o’clock, Monday, 1999, etc.):

I’ve been waiting since 8 o’clock.

We can use “Since” with:

8 o’clock
Monday
12 May
April
2001
Christmas
lunchtime
we arrived

For example:

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

For example:

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 I 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)

WHEN & HOW LONG

Compare when … ? (+ past simple) and how long … ? (+ present perfect):

A: When did it start raining?

B: It started raining an hour ago or at 1 o’clock.

A: How long has it been raining?

B: It’s been raining for an hour or since 1 o’clock.

A: When did joe and Carol first meet?

B: They first met when they were at school. OR a long time ago.

A: How long have they known each other?

B: They’ve known each other for a long time. OR since they were at school.

We say:

lt’s (= it is)

or It’s been (= it has been)

a long time

six months (etc.)

since something happened

Take a look at these examples:

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 Mrs Hill die?)