Translation:Where is the hospital?
The question assumes the speaker knows that there's a hospital in the area whereas your question seems to imply no such knowledge. That said, I'd say I don't think it is unacceptable, but the given translation is more idiomatic.
I think the difference between affirmative and interrogative sentence (involving zai nar) is subtle but still substantive. When we use "zai nar" as question (where), "nar" is in third tone; in writing, Chinese character "na" has an additional radical. Where as a statement (there), nar is pronounced in fourth tone. In writing, Chinese character nar is without any radical
Yes, indeed; it's the "mouth" radical (the little square box) that indicates the question; the mouth radical appears in other question words as well. As for the difference being "subtle but still substantive," the difference between English "where" and "there" is only one letter in writing (and the initial sound in pronunciation). I think the difference between 哪儿 and 那儿 is as distinct to native Chinese speakers as the difference between "where" and "there" to native English speakers.
I like the analogy. And since one can't be used in the place of the other, generally speaking, it is quite clear which one is meant when spoken.
so if you say....医院在哪儿吗？Then that means "is the hospital there？“ does the 吗 make the difference between where and there?
The 吗 marks a yes-no question specifically, not questions in general. So you only get 吗 and question words like 哪儿 in the same sentence in two scenarios:
- The question word is in an embedded question: 你知道医院在哪儿吗？ “Do you know where the hospital is?” This is still a yes-no question “Do you know x?” Only that x is an embedded clause “Where is the hospital?” And that embedded clause is in turn a question which contains 哪儿.
- When the question word is actually not a question word at all but a so-called “indefinite pronoun”. In English these are usually formed with “any-”. For example: 你要去哪儿吗？ “Do you want to go anywhere?”
In this sentence there is no embedded clause, so if you add 吗 the question word would have to be interpreted as an indefinite pronoun: “Is the hospital anywhere?” Which actually sounds even weirder in Chinese than it does in English because the sentence sounds like it’s already established that there is a certain hospital we’re talking about. It doesn’t make much sense to ask whether it exists at all then.
Does that make sense?
Adding to AbunPang's reply, remember that 哪儿 (nar3) means "where", and 那儿 (nar4) means "there".
What about "which"? How do you ask "In which hospital?" (I.e. as a response to "it is in the hospital).
Interesting that I've just spent about 8 steps learning and reinforcing xi, yuan and shou, and the first actual sentence I get is "where is the hospital?" - composed entirely of words which have not been taught in this lesson.