To say thank you in Thai, say khop khun (ขอบคุณ). Add krub (ครับ) if you are a man and ka (ค่ะ) if you are a woman, giving you khop khun krub or khop khun ka. Those two little endings turn a plain thanks into a polite one, and Thais notice every single time.
There is no separate word for "please" you need to bolt on here — the warmth lives in that ending and, often, a small bow of the hands. Get khop khun and its particles right and you are covered from the airport taxi to the night market.
The base: khop khun
The root is khop khun (ขอบคุณ), and it rarely travels alone. Cap it with the particle that matches your gender and you have a complete, polite thank-you.
ขอบคุณครับ
khop khun krub
Thank you (male speaker)
ขอบคุณค่ะ
khop khun ka
Thank you (female speaker)
Say it like you mean it
To thank someone warmly, add mak (มาก), "much." Double it up for real gratitude — after a big favor, khop khun mak mak is heartfelt rather than over the top.
ขอบคุณมาก
khop khun mak
Thank you very much
ขอบคุณมากๆ
khop khun mak mak
Thanks so much (extra warm)
The gender particle still goes on the very end: khop khun mak krub or khop khun mak ka.
Casual thanks among friends
With close friends or someone clearly younger, Thais often swap in khop jai (ขอบใจ), a friendlier, more familiar thanks. It is affectionate between equals, but there is a catch.
Use khop jai (ขอบใจ) only with friends or people younger than you. Said to an elder, a boss, or a stranger it sounds like you are talking down to them. When in doubt, khop khun (ขอบคุณ) is never wrong.
How to answer "thank you"
When someone thanks you, the reflexive reply is mai pen rai (ไม่เป็นไร) — "no problem, don't mention it." For a warmer "my pleasure," reach for yin dee (ยินดี).
ไม่เป็นไร
mai pen rai
You're welcome / no problem
ยินดีครับ
yin dee krub
My pleasure (male speaker)
That first phrase is a whole philosophy in three syllables; our guide to mai pen rai unpacks why you will hear it a dozen times a day.
Add a small wai
For genuine thanks — to a host, an elder, someone who went out of their way — raise your palms together in a wai (ไหว้) as you say khop khun. You do not need it for a shop clerk handing back change, but for real kindness the gesture says as much as the words. The deeper the bow and the higher your hands, the more respect it signals — a slight dip for a peer, a fuller wai for someone you truly want to honor.
Men, watch this one. Because you will hear "ka" constantly from female shopkeepers and servers, it is easy to start echoing it back. Always end with krub (ครับ) if you are male — your particle follows your own gender, never the other person's.
Keep learning Thai
Thank-yous are the phrases you will reach for most, so they are worth drilling until they are automatic. Start with the free essential Thai phrases in the Pretalk app, where audio and spaced repetition help khop khun krub and khop khun ka roll off the tongue without a second thought — exactly when a smiling street vendor is waiting for a reply.
