How do say good day in Thailand?

Answer 1

to be polite say "sa-bai-dee-mai na kah" if you are a girl

but if you are a boy then you have to say "sa-bai-dee-mai-kahp?"

If she/he is your close friend, just say "pen-ngai-bang?" It's an informal way to speak with friends.
have nice day

Answer 2

1.Sa bay Dee mai

2.khun pen yang rai bang <----- doesn't make sense

First of all number 2 doesnt make sense at all. To be polite you say Sa buy Dee mai kaa (girls) and for boys you say Sa buy Dee mai kap?

If you just say it regularly to someone who's your age or your friend say number 1.

Answer 3

kun-yoo-tee-nai - krub/ka (krub for male/ ka for female) คุณ - อยู่ - ที่ - ไหน - ครับ/ค่ะ