I took one of those quizzes the other day, the ones that test your knowledge of the trickiest parts of English grammar, and I got a few new ideas for Grammar Check posts. This month, I thought I'd tackle another of those confusing homophone pairs: then and than.
Then means "at the time mentioned1." It's used to denote the passing of time.
Michael went to the movies, then he picked up his groceries.
Than is comparative. It's "used as a function word to indicate the second member or the member taken as the point of departure in a comparison expressive of inequality2."
Michael would rather go to the movies than go grocery shopping.
Much like with "affect" and "effect", you can use a little trick to help you remember. Then allows you to cycle through events. "This happened, then this, then this." If you use than, you are comparing things against each other. "I'd rather sleep than work. I'd rather have ice cream than spinach."
I'm a big fan of mnemonic devices like that. English is a... quirky language, to say the least, and it helps to come up with a few shortcuts for particularly sticky situations. Hopefully this one will help you out in the future.