Questions & Answers about Кто ещё хочет чай?
Кто means who and is the question word asking about the person. In this sentence, кто is the subject:
- Кто — who
- хочет — wants
So literally, the structure is Who wants tea?
Because the sentence is asking which person wants tea, кто naturally comes first.
Here ещё means else.
So:
- Кто хочет чай? = Who wants tea?
- Кто ещё хочет чай? = Who else wants tea?
In other contexts, ещё can also mean still, yet, or more, so learners often notice it has several meanings. In this sentence, the meaning is specifically else.
Хочет is the 3rd person singular form of хотеть (to want).
It matches кто, because кто is grammatically treated as singular in Russian when it means who.
So even though you are asking about any person, Russian uses singular verb agreement:
- Кто хочет...? = Who wants...?
Not хотят.