It was suggested at this question that a question about a single language is off-topic, being more appropriate for a Stack Exchange site dedicated to that language. What do people think of this idea?
The tone and nature of an answer on a linguistic site is expected to be different. For example, when learning Chinese in order to speak it, it's pointless and counter productive to say why things are as they are-- this word order is correct with respect to the standard dialect & this one is wrong.
On a linguistics site, finding out the motivation for word order is appropriate. For example the reason why Germanic languages change to VSO when a adverbial phrase has been fronted is interesting (and a bit technical), but a learner of German/Swedish/Icelandic probably shouldn't care about the motivation, they just need to know that if an adverbial comes first in a sentence, then swap the normal places of the verb and subject.
I do not find such questions off-topic. The English Language and Usage site's FAQ says:
Questions on the following topics are welcomed here:
* Usage, word choice, and grammar * Etymology (history of words’ development) * Dialect differences * Pronunciation (phonetics and phonology, dialectology) * Spelling and punctuation * Problems encountered by people learning English
Though this needn't be interpreted as an exhaustive list, it also does not encompass the breadth of questions that can be asked about English. Specifically with reference to the linked question, it is possible to ask questions about English with reference to other languages and/or linguistic theory in general; such questions would be questionably germane to a site about "English Language and Usage."
What's more, linguistically interesting questions on the English Stack Exchange can get drowned out by the stock in trade over there, chiefly copyediting and lexicographical questions. Thus, questions directed primarily towards an audience of linguistics enthusiasts would be hard to browse/answer if posted there.
So, the fact that a question is about English is not in my view prima facie evidence that it is off-topic. Insofar as it addresses a linguistically pertinent issue of English, I think it should be welcomed here.
I would say questions that make reference only to one language may be on-topic, depending on the rest of the content of the question of course. One may observe an interesting paradigm in English, for example: that the sentence in (1) is ambiguous between a comparative (the highest mountains for any mountaineer, requiring for truth that no other mountaineer climbed as high of mountains) and an absolute reading (the highest mountains of all, irrespective of whether any other mountaineer also climbed them), but (2) is not ambiguous, having only the absolute reading.
- John climbed the highest mountains
- John climbed Italy's highest mountains
One may want to know if any known constraint or fact(s) about grammar predicts this pattern. I would say such a question would clearly be on-topic.