For and since

For and since

For

Use the present perfect simple tense with for to indicate the duration of the action:

for two months,

for a year,

for a long time

Examples

1-I have lived in Makkah for 8 years.

2-She has studied for 2 hours.

3-We have waited you for a long time.

Since

Use the present perfect simple with since to indicate when the action began:

since yesterday,

since last June.

Examples

1-I have lived in Makkah since 2012

2-She has studied since she left school.

3-We have waited you since you phoned .

How long ......?

Q: How long has the clothing store been in operation?

A: It’s been in operation since 1975.

It’s been in operation for 40 years..