qwerty wrote:As I was reviewing Lesson 1 I stumbled upon this thing with の: can it be (I'm sorry that I can't explain it better) repeated? For example, how would I say "Takeshi's Japanese teacher"? Can I just use の twice, i.e. たけしのにほんごのせんせい ? Somehow it doesn't feel right mostly because there would have to be an established order in which the clause is evaluated for it to make sense.
As far as potential ambiguity is concerned, I don't think it exists in this case. It is pretty clear what たけしのにほんごのせんせい means.
The tricky part is that sometimes Japanese simply adjoins one word to another (particularly kanji compounds) to make a new compound and sometimes the particle のis used between the words. I'm not sure if there's a specific rule for when to use it or not, I tend to just go with my gut. Here, I think たけしのにほんごのせんせい sounds kind of clunky (like you said, feels like too many のs), and I think にほんごせんせい is a valid compound here, but Google gives more hits for にほんごのせんせい than にほんごせんせい. Still, that doesn't mean that にほんごせんせい wouldn't be preferable when there's another のthere... Maybe some other Unilangers can weigh in here? Send Yasna and/or Hashi a PM, they speak Japanese pretty well.
In any case, I don't think たけしのにほんごのせんせい is horribly wrong, it's certainly fully understandable.