I mean something like Klingon or Quenya when I say fictional languages. Are questions about these languages on-topic for this site?
I say yes. Fictional or not, they are still languages right?
Though these languages are purely fictional, questions can still be about the learning of these languages. I would expect some differences in the questions asked as they are not actually used in real life but can be learned by eager fans. Instead of the languages people actually use, I think we are flexible enough to introduce an interesting and exciting new topic to our site: fictional languages.
Now if this happens, we must make some restrictions on these languages as these questions are new and we just entered public beta, thus the need for borders and rules to all of our different types of questions.
Fictional languages are pretty similar to real languages, with the main difference being that there may not be a population or country that speaks the language. It's still gonna have grammar structures, vocabulary and maybe even a character set.
The only situation that I could see leading to trouble is if one of these languages is incomplete; how are you going to learn a language that hasn't been fully designed? However, this might not be even be a problem, it may even make to be an interesting question.
We could always use the constructed-languages tag if we need to, but I suppose the use case for that would be pretty limited.
Our site is "Language Learning", it's about the learning a language, so if language specific questions are about learning the language, it would be on-topic.
Questions shouldn't be about the language's spelling/syntax/semantics/etc., they should be about learning it.
Some examples of off-topic questions (feel free to edit more in):
- What does <insert quote from a book> mean?
- What is the origin of <insert idiom here>?
- When do you pronounce <insert letter here> in <insert language here>?
That said, questions which apply to the process of learning a specific language, should somehow apply to a broader range of "similar" language. I'm not saying that all questions falling under this should be left open, if it has some other flaw such as being primarily-opinion based, it should be closed.
In other words, the on-topicness of the question is not based on the language, but on the question.
If the question is about learning, your target language can be Spanish, Esperanto, American Sign Language, or Klingon. It doesn't matter.
There will be very few (if any--I can't think of one now) questions that are unique to learning fictional/created languages. If such a question exists, though, it ought to be permitted, granted it is about learning.
It's hard to understand what you mean by a "fictional language." If a language exists, it exists. If people speak it or write it, it is real. Perhaps you mean natural (occurring naturally in the culture of a people) vs. synthetic (invented for a book or a movie or for fun or other purposes). Any way you slice it, languages are languages and should be fair game on this site (assuming they're meant for communication between humans and humans and not between humans and microchips).