I can run faster than _. (1) him (2) he?
Which is correct?
You know more about this than me.
You know more about this than I.
The second sounds unnatural, but I think it is correct because a trailing know is implied.
My guess is both are correct. The first than is used as a preposition while the second one is used as a conjunction.
Note however, to me, the first sentence means you know more about this than you know about me while the second one means you know more about this than I know about this.
The first uses than as a preposition having me as its complement. The second uses than as a conjunction to introduce the elliptical clause I (do). ‘The Cambridge Guide to English Usage’ reports that:
No one need hesitate to say You know more about this than me.
The second sentence is, indeed, the correct one. If in doubt, always try to fill in the missing words - just as you did.
If you don't, your sentences might get misinterpreted. Consider this example