Sitting here at supper, I just watched one of my cats use some pretty strong language with one of my other cats. It was some very measured chattering to let him know she didn’t enjoy his presence. Chickens most definitely have a language - the egg song, the danger song, the rooster call, the check-in with each other, the check-in with the farmer. My point being, animals all around us use language if we are willing to accept that it is different from our own.
If anyone is interested more in Bonobos and wants to learn more about that species and the way that species connects with humanity I suggest the following book:
And almost certainly: cetaceans too.