Practice: khrap and kha
What you will be able to do
Reach for the right politeness particle without thinking, including the statement and question split that women make and men do not.
Thai marks politeness with a particle at the end of the sentence, and it depends on the SPEAKER's gender, not on who is being addressed. Men have one form. Women have two, and choosing between them by sentence type is the part that takes practice. Leaving the particle off is not a neutral choice: it reads as blunt.
Which particle?
a man making a statement
A man says ครับ (khráp), high tone, and it does not change between statements and questions. That is the whole rule for men.
Which particle?
a man asking a question
Still ครับ. Men have one form; women have two.
Which particle?
a woman making a statement
A woman says ค่ะ (khâ), falling tone, in a statement.
Which particle?
a woman asking a question
A woman says คะ (khá), high tone, in a question. That switch between ค่ะ and คะ is what catches most learners.
How is this romanised on this site?
ค่ะ
khâ. ค is an aspirated kh, like the start of khaki, so writing it kâ drops the aspiration. It is the commonest particle mistake foreigners make.
Which particle follows นะ?
a woman saying นะ then the particle
After the softener นะ it is always นะคะ (ná khá), even in a statement. That is the one regular exception to the statement rule.
Is this correct?
a man saying ค่ะ
No. The particle follows the SPEAKER's gender, not the listener's. A man saying ค่ะ is a common and very noticeable beginner error.
How does that land?
leaving the particle off entirely
Not neutral. It reads as blunt, and with strangers or anyone older it reads as rude. Add it every time until it is automatic.
What else does this word do on its own?
ครับ
ครับ on its own works as yes and as I am listening, which is why you hear it repeated down a phone line.
Add the particle for a woman apologising
ขอโทษ
ขอโทษค่ะ, khǎw-thôot khâ. It is a statement, so it takes ค่ะ.
Add the particle for a man asking a price
เท่าไหร่
เท่าไหร่ครับ, thâo-rài khráp. How much? A man uses ครับ for both statements and questions.
Common mistake
Do not mix the genders. A man saying ค่ะ is instantly noticeable. Pick the particle that matches you and use it every time until it stops being a decision.