[throwaway29103]

When talking about language (I see in the comments below), I think it is useful to differentiate between the potential capabilities of human languages (i.e., all baby humans seem to be able to learn to adult native level of proficiency any human language, regardless of were where their parents from) and the possible effect that using a particular language might have in the speaker or in the people receiving speech in that particular language, i.e., the expressive capabilities of that individual in that language or of the vocabulary of that language specifically (e.g., crafting a joke: how do you make an egg laugh? Tell him a yoke).

What I mean is that language ability of humans and language ability of animals are not comparable; they are so different that in fact, language ability (regardless of the externalization of that language, by speech, text, signs, touch), looks very much like intelligence (meaning the intrinsic ability for language production and not the specific proficiency at some sort of externalization).

If you happen to spend enough time around animals and child humans you will quickly see that after a couple of years, kids can understand and use recursive / referential structures in a way that pets cannot. Pets seem to understand individual words, tones, and maybe "not". Think of "bring the comfy ones that your grandparents bought you to keep your feet warm" - a sentence a 3 year old can perfectly understand. No matter how much you spend teaching/training a dog that has lived in the same environment since its birth, the dog will not react to it bringing you the yellow slippers (unless you specifically trained the dog to associate the word "comfy" or "feet" to some specific slippers). The current state of parametric language models resemble much more that of a very memorious dog than that of a human.