Since and For - English Grammar - English Free Test
We use since when we give the beginning of the time.(for example:since Monday)
We use for when we give the length of the time.(for example:for three days).
Examples:
Since:
- I have worked here since 2004.
- I have had this car since October.
- I have known your parents since 1978.
For:
- I have worked here for three years.
- I have had this car for three months.
- I have known your parents for a long time.(or for 29 years)