Can you check this sentence for me?
Is this correct/natural to say?
"걔의 엄마는 때문인가?"

Question

Answer

반가워요!

Q: "걔의 엄마는 때문인가?" "Is it because of their mom?"
A: (Peer speech) 그게 걔 엄마 때문이야?
(Polite speech) 그게 그 사람(의) 어머니 때문이에요?
(Honorifics) 그게 그 분(의) 어머님 때문입니까?

Answer

I was trying to say, "Is it because of their mom?"

Answer

Good! but I couldn't understand exactly. What do you mean by that?