In Thai, to say "thank you," you say: ขอบคุณ
Pronounced: khàawp-khun For a more polite form, men usually add ครับ (khráp) at the end, and women add ค่ะ (khâ). So:

• For men: ขอบคุณครับ (khàawp-khun khráp)
• For women: ขอบคุณค่ะ (khàawp-khun khâ)

This is the most common and polite way to express gratitude in Thai!