When do you use the word "Phi" in Thai?

You use the word "Phi" when you call someone who is not much older than you. For example, my younger brother calls me "Phi Gor" and I call him "Nong".

For people who are a lot older than me, I call them uncle or aunt even if they are not my relation. If the man is older than my father, I call him "Lung". If he is younger, I call him "Ah". If the woman is older than my mum, I call her "Ba". If she is younger, I call her "Na"

"Khun" is the polite way of saying "you". We use it in front of people's name like you use Mr. and Mrs. I don't usually use it.

I think it's better for you to use the word "khun" in front of someone's name.

- Nattawud