Word order in "Where is the classroom for the Japanese class?"
The Classroom lesson has the following sentence:
I find the placement of のぎょうしつ somewhat unexpected; I would have put it right after 日本語のじゅぎょう.
Is this a style thing, trying to avoid an expression containing two のs? Or what is going on?
I'm afraid that your question doesn't make much sense to me. Grammatically the sentence is fine. じゅぎょう is a lesson or a class. きょうしつ (not ぎょうしつ) is a classroom. 'Where is the classroom for the Japanese class'. There are many sentences which have の repeated. To say this is strange would be like saying that there cannot be two possessive nouns in an English sentence. どこの is equivalent to asking 'which' or 'the one where'. (I am aware that the last bit sounds a bit strange).
Oh - maybe I misunderstand the sentence? I thought it was a sequence of possessives, and so I would have said: the room of the class of the Japanese, where is it?
I had never seen どこの + noun before, and I'm finding it a bit hard to translate literally. "As far as the Japanese class is concerned, where of the classroom is?" - sounds awful, doesn't really make sense.
I agree with BJCUAI that どこのきょうしつ has no problem, just there is no literal equivalent in English. Compare it with 誰のお父さん, which you can easily translate to "whose father". The logic is the same, only you don't have an English word for "of where" like "of who".
Also, I think it may be strange to say 授業の教室. Although 授業 is often translated as lesson or class, it's genuine meaning is "teaching". It is not natural to say something like "Today's teaching is boring" for "今日の授業は退屈だ” and thus the word is so translated. The idea of "the classroom of teaching of Japanese language" is a bit strange to understand. If we had to say, we should say 日本語の授業を行う教室, but that is also not the most natural way to say it. Rather, we can skip 教室 altogether and say 日本語の授業はどこですか？, just like saying 本はどこですか？
I wholeheartedly agree with you. As it seems that this program tends to use 授業 in a different way than I am accustomed, I didn't want to stray from their usage. I believe most Japanese would favor クラス for many of the occasions where 授業 is used in Duolingo. Also, in Japan, the Japanese language in education would not be 日本語, it would be 国語. 日本語のクラス would be for foreign students of Japanese.
So, as you said, 授業 would be the training, teaching, lesson aspect. The physically assembly of humans to do 授業 would be クラス.
All of this is not to detract from your explanation, which I believe was likely more appropriate than mine.
I appreciate how you always follow up on your questions and are very proactive in your studies. With that attitude I think you will do well in Japanese or whichever language you pursue.
Again, just so you don't get in the habit of saying the word incorrectly, it is きょうしつ, not ぎょうしつ.
Is it about the emphasis? Here are some sentences:
日本語のじゅぎょうは どこのきょうしつですか? - Where is the classroom for the Japanese language class?
日本語のじゅぎょうのきょうしつはどこですか? - Where is the classroom for the Japanese language class?
日本語は どこのじゅぎょうのきょうしつですか? - Where is the classroom for the class of Japanese language?
どこは日本語のじゅぎょうのきょうしつですか? - Where is the classroom for the Japanese language class?
The "は" particle appears in four different places, which changes the emphasis on the topic of the sentence. That's my understanding of it, but I'm not really sure which ones of those actually get used in daily conversations.
According to Keith_APP's comment, the sentences 2, 3 and 4 probably sound unnatural... so that leaves option 1 . Or just:
日本語のじゅぎょうはどこですか? - Where is the classroom for the Japanese language?
日本語の クラス (or きょうしつ)はどこですか? - Where is the Japanese language class (classroom)?