how different are the languages from each other? are there many cognates or have they diverged too significantly?
In Felis Artis, language evolved across the globe with four big sections, huge language families that encompass thousands of them:
Primates (Humans are the only example in this category)
Mammals (Cats and Dogs, alongside a select few other species)
Aquatic creatures (Fish and amphibians)
Human language in this universe evolved first, with the final language family to evolve into existence being that of reptiles. Mammals and Aquatic creatures evolved a few thousand years after each other, which is surprising in those in anthropology, but I digress.
Mammal languages converge a LOT based on species. The length of a muzzle, amount of teeth, muscles in the face, and lips (or lack thereof) can impact how a language sounds, and therefor makes it harder to understand without something to help with it, like a translator or something of the like.
I should also note that the smarter birds (Corvids and some parrots) are in this category. Not because they are mammals, but because their languages are mammalian in origins.
I've made a handy little chart for the mammalian language family :)
Note, I forgot to add Modern Tribemew to this tree. It's meant to be on the little edge/outcropping that Towngrowl has before merging into Townspeak. Whoops!
It stems from Barkgrowl, a language spoken by wolves, before humans. As you can see, it was the first language in the family spoken, and evolved into all of languages.
To answer your question anon, yes, there are many cognates. Sometimes it's hard to tell, but most languages share a solid 40% of their syllables and basic affixes from Barkhowl, and also nearby languages. Towngrowl slowly began to diverge into Straytalk and Townspeak once the Vigils left the area, and it's language pool is pretty similar.
Once Felinepurr evolved into Old Tribemew, the influx of domestic cats began to pour into the territories and the Vigils began to form, thus the huge amount of divergences in the area, but it also became a problem. Very quickly. I'll get into why in another post when I have the time, but it's quite interesting :)