For two words that mean totally different things, then and than are mixed up pretty often. Why? Because visually, they're only off by one letter.
It's like accidentally saying Paris when you mean Perez. Both may be Hiltons, but they certainly are not the same person. (Although now that we think about it, we've never seen them together…)
- The word then implies an element of time and can mean next or at that time.
- You use the word than when comparing things or when introducing an exception or difference.