Breakdown of คุณ สบายดี ไหม ครับ
ครับ
polite particle (male)
คุณ
you
สบายดี
to be well
ไหม
question particle
Questions & Answers about คุณ สบายดี ไหม ครับ
How do I answer "yes" or "no" to this question?
Since this is a ไหม question, you answer by echoing the main verb. To say yes, you just reply สบายดี (well). To say no, you put ไม่ (not) before the verb. Note that Thai speakers usually drop the ดี (good) for the negative, so "no" becomes just ไม่สบาย (not well / sick).
Where is the word for "are" in this sentence?
You don't need one! In Thai, describing words like สบายดี act as verbs all by themselves. The literal sentence structure is just "You well [question word] [polite particle]."
Does the polite particle ครับ mean I am asking this question to a man?
Not at all. The polite particle used depends entirely on the gender of the person speaking, not the listener. ครับ is used here because the person asking the question is male. A female speaker would ask this exact same question but end it with คะ.
Why does ไหม come before ครับ? I thought question words go at the very end.
ไหม is placed at the end of the statement to turn it into a question. However, polite particles like ครับ and คะ are always added at the absolute very end of your phrase, meaning they will always follow the question word.