Translation:Why is the milk boiling?
Doesn't this mean more why are you boiling the milk?
I think 끓다 is intransitive.
If someone is boiling the milk, it should be 끓이다 or 삶다.
牛乳가 왜 끓나요?
I wonder if double 받침 means it's native Korean.
Some words just have double 받침s like 끓다, 잃다, 없다, 있다.
Yeah but I can't come up with any Sino words with 겹받침, how about you?
I feel like that is the general pattern but I'm not totally sure.