i don't think this question will stay, but I'll have a go at it.
then and than do not sound the same when spoken, they sound similar, but not the same. the 'e' in 'then' is a more closed sound than the 'a' in 'than'.
you might want to compare other words with the same sounds:
ben, ban
send, sand
lend, land
'then' tends to be used when talking about sequences. "i do this, then i do that", it can also be logical sequences: "if you rob a bank, then you will go to jail"
'than' tends to be used more for comparisons: "I'd rather have a nice car than a small payrise", "there's nothing more satisfying than spending the night with your friends".
although I'm not a linguist so I'm probably missing a lot of uses.
For the most part, they are pronounced differently and shouldn't sound the same. Anyways, 'than' is used when you are making a comparison. 'Then' is used in different ways. "It was an easier time, then (at that time)", "Go straight, then (next) turn left at the light", "If you are him, then (in that case) come forward". There are some more ways to use then here.
BurnOutBrighter6 t1_je8nilj wrote
*write
No they don't sound the same.
"Then" means "happening next". I'm going to work, and then to the gym, then driving home.
"Than" is for comparisons. You are taller than me. Mexico is hotter than Canada.