These sentence-final particles are the backbone of Thai politeness. Using the right one — or none — signals your register instantly. Master ครับ/ค่ะ before anything else.
ครับ
khráp (high)
A polite ending commonly used by male speakers in statements, questions and requests. A useful default when speaking to someone you do not know well. It does not make every command sound polite.
ขอบคุณครับ
Thank you.
ค่ะ
khâ (falling)
Commonly used by female speakers for polite statements and replies. Say ค่ะ with a falling tone.
ขอบคุณค่ะ
Thank you.
คะ
khá (high)
Commonly used by female speakers in polite questions. Say คะ with a high tone. This is also the form after นะ: นะคะ.
จริงหรอคะ?
Really?
นะ
na
Can soften a request, invitation or reminder, or invite agreement. Its effect depends on the situation. Common polite combinations are นะครับ and นะคะ.
ไปกันด้วยนะ
Come along, yeah?
สิ / ซิ
si
Can encourage someone or add insistence. Delivery and context matter; it may sound impatient. Learn it through a specific exchange rather than adding it to every request.
ไปเลยสิ
Just go already!
Stacking rules
- นะครับ / นะคะ can make a request, invitation or reminder sound softer and polite.
- Context and delivery matter. A polite ending does not remove the insistence that สิ can add.
- ค่ะ (falling) for statements; คะ (high) for questions — the tone changes meaning