From my post-human setting.
There was an early period where demons largely controlled the world, and so many cities were founded by demons and some cultures use writing systems derived from the demons. The demons themselves are a multi-racial, multi-planar civilizations that tend to exploit "lesser" worlds.
Goblins all speak (at least) two languages. One is a tribal language which is not taught to outsiders and changes rapidly. The second is a "market" language for talking to outsiders (including most goblins).
Gnrolls have very subtle secondary sex characteristics and all appear male to other races. Indicating anyone's sex is considered obscene.
Humans are recently extinct.