There is a variety of people who come here with different intentions. There are people who are interested in particular conlangs (e.g. the languages of Tolkien), and there is no debate that their questions are perfectly appropriate here. But there are of course also people who want to make constructed languages themselves¹, and their questions will be much more linguistic in nature. I would go as far as to claim that for anyone who wants to make a naturalistic conlang² will predominantly have questions that might just as well feature on linguistics.SE. The obvious question then becomes whether these questions are on-topic here. Some example questions that fall into this grey zone:
- What is the difference between tense and aspect?
- What are common origins of accusative case markers?
- Consider an isolated, close-knit community; which characteristics is their language likely to have?
- What is the difference between an Isolating and an Analytic language?
Of these, 1. and 4. are questions on linguistic terminology, while the other two ask about tendencies in natural languages. All of these questions would presumably be welcome on linguistics.SE. At the same time, these are questions that an aspiring conlanger might have and (moreso in the case of 2. and 3. than for the terminology questions) will need answers to to properly construct their language.
Are these questions on topic here?
¹ such as myself
² which is likely a majority among conlangers