Form and rules
How it works
Use for + period of time: for three hours, for a long time.
Use since + starting point with a perfect tense for a situation continuing to now: since Monday, since I moved here.
Use from to mark a starting point when the end is stated or implied: from Monday to Friday, from 9 until 5.
Do not use since with a finished past duration: I lived there for two years, not since two years.
Since can introduce a clause: I've known her since we were children.