FOR OR SINCE? EXERCISE 1 (ESL)

Grammar review For or since? — the key distinction

Both for and since are used with the present perfect tense to talk about something that started in the past and continues now. The difference is what follows them.

FOR + duration (a length of time):
for two hours, for a week, for six months, for three years, for a long time, for ages
“They’ve worked here for five years.” (five years = duration)

SINCE + starting point (a specific moment in time):
since 2015, since Monday, since last summer, since I was a child, since this morning
“They’ve worked here since 2019.” (2019 = when it started)

The quick test:
Can you replace it with “a length of time”? → for
Can you replace it with “starting from that moment”? → since

Common error:
✗ “She hasn’t called me since two weeks.”
✓ “She hasn’t called me for two weeks.” (two weeks = duration)