As far as I know, then is used in a conjunction and in time-related sentences; than in all other cases. I believe that these are correct:
- Because I'm older than she, I should be the first chosen;
- I loved her and then she died;
- If it rains [then] it pours;
- I've had more then enough;
- Would you rather be a mouse then a rat?
- Who, other than you, likes the color red?
Or not? Can someone help me out clearing the mud? I think I'm 90% there, but I like to finally understand it completely. If you have other uses of then/than that I missed, please add yours.