Since and For

[kmgh]

Are there any other instances or rules for "since" and "for"?

I know that for is used for general periods of time - 2 hours, three days, one month and since is used for a specific time - 1998, January, last week, one month ago.

Thanks so much!

[Tdol]

'For' has many other uses as a preposition, without referring to time- it can indicate purpose (I went for a coffee). 'Since' can also be used to mean 'because' (take an umbrella since it's going to rain later)