By Marina Pantcheva
The word then indicates time or a sequence of actions.
It happened there and then. (time)
Back then, people had to walk to work. (time)
We ate and then went to bed. (sequence of actions)
You must first fill in your tax form and then go to the tax office. (sequence of actions)
The word than indicates comparison.
John is taller than Peter.
He spends more than he earns.
It is easy to remember that then and than have different functions, but the challenge is to remember which one expresses time and which one is used with comparisons. Here is a little tip: the word timE has e in it, so use thEn; the word compArison has a in it, so use thAn with it.