I have already more than once faced a situation when the answer to the question would differ depending on my knowledge of whether the OP was a curious Russian native speaker or a foreigner learning Russian and stumbling over some difficulty.
I understand, that SE's are supposed to be the FAQ sites, however in general they are not really. Most questions are welcome, even if they are not very probable to be faced by many people (especially in programming-related sites). So SE's are not the frequently asked questions web-sites.
From this point of view, it does not make sense, in my opinion, to provide a detailed, dictionary-like answer to each question. Besides, long answers easily get too complicated even to read, not just to understand.
A solution I see would be to specify in the user's profile the native language of the user. It would also allow providing examples which are more probable to be clear for this particular user.
As an example, consider the opposite situation, with an English.SE site. If I (a native Russian speaker) would be interested in the use of articles, the responder would have to struggle to explain them to me. If I were a German, the answer could refer to the German equivalents.