"How many chairs are there in the room?"
First, think about the place. The place is the room (部屋 - へや - heya).
Then what do you want to count. In the example, you want to count chairs (椅子 - いす - isu).
And the rest of the sentence is the question + verb (いくつあちますか - ikutsu arimasu ka).
Now you just need to use the particles (には - niwa and が - ga) to connect everything:
A literal translation would be:
"In the room, as for chairs, how many are in there?"
I hope it can help someone.
I disagree, I think the literal translation would be
"As for (in) the room, how many chairs exist"?
Though of course the order is actually "The room: as for it, chairs - how many exist?"
But I would think you could express it as
My understanding is this might be used if perhaps wanting to contrast how many chairs vs other objects might be in the room, or if it's the first time chairs have come into the conversation.
In my class, the teacher explained that the safest place to put the counter word is immediately before the verb. Although it's possible to put the counters elsewhere, he said it was tricky and would require other changes. Ikutsu is asking how many and I believe that it should be in the same place that the counter would be in the answer. For example:
Isu wa heya ni ikutsu arimasu ka?
Isu wa heya ni futatsu arimasu
If I've understood correctly が indicates the subject while は indicates the topic of a sentence and when something is both subject and topic you would drop the が. However if the topic was the room one would still say both: へやには because the に is too important to drop.
But dont take my word for it
I'm not entirely sure but in the question は makes it sound to me like "as for this object, how many are there?"
が would only make sense to me if someone misunderstood the question and you repeat that you're asking about the amount of that specific object. "How many chairs (は) are in the room?" "Sorry, how many what?" "i asked, how many CHAIRS (が) are in the room?"
Edit: I read the og post as "correct" instead of "incorrect". Duo doesn't like casual speech.
I'm not disagreeing with 2e_su's answer, just explaining why it was accepted. I didn't know that の was mostly used by women. I thought when the particle was used to say something was an explanation to a question, a plain の was feminine versus んだ was neutral or masculine, but neutral when used as a question. Ex: 椅子が五つあるの。 versus 椅子が五つあるんだ。
Since you seem so good at Japanese. I was wondering why Duolingo prefers to put 部屋に at the beginning of the sentence. I guess it is still grammatically correct, but I have learned that it is more natural to have the topic at the beginning, with the exception of time. Is this an exception, has Duolingo made a mistake or am I simply in the wrong here?
When I hear しつ alone, I think about "quality" (質). Even though you hear it in a lot of compounds, you don't really use 室 alone in the same meaning, so the answer is no, it isn't. Maybe you could use 室内（しつない), but maybe that is too ambiguous for "in the room" since it means also 'indoors'.
"Heya ni wa": "heya ni wa isu ga arimasu". In the room, there is a chair. "The room' is the subject, but room also describes situational context for the sentence so it needs both ni and wa.
"Heya ni": "Heya ni isu wa..... Etc etc" In this situation "the chair in the room" is the subject. heya is only a descriptor. This leaves you free to talk about the chairs further. Like... The chairs in the room are red.
I was marked right for using "椅子が部屋にいくつありますか" And there's no は.
My understanding is that by putting 椅子 first, then the focus is on the chairs as it's implied with the が (since the number of chairs is the new information).
But if you put the room first, then it becomes the focus - 部屋には.
Someone else can correct me if I'm wrong, but that's how I figured it.