Am I cooler THEN you?

Then and than.

This is another huge pet peeve of mine.  All the grammatical errors that I rant about bother me, but this is one that really rubs me the wrong way because if you're going to make a comparison between two things, do it right.

It is very simple. Use than when comparing, and use then every other time. That's all there is to it.

Than: comparison
Then: at a point in time/addition to

So the title of this post is wrong. I am not cooler then you, I am cooler THAN you. Never use then in a comparison and you'll be golden!