sà-baai dee măi khráp?
phŏm sà-baai dee khráp
sà-baai dee măi khá?
chăn sà-baai dee khâ
note the different tone for khá in questions
You can add khráp or khâ to the end of almost any sentence. If you are having a conversation, there is no need to use it every time you speak but feel free to use it liberally. You should always try to include it in your opening and closing sentences.
You may also use khráp or khâ on their own as an acknowledgment or affirmative answer. If you listen to a Thai man on the phone you will often hear ‘….khráp…..khráp….khráp‘ acknowledging what is being said at the other end. Similarly, when you collect your parking ticket from the attendant at a car park he will usually acknowledge you with a simple khráp. You can reply likewise.