Came across a page with biographies of some chimpanzees and bonobos who have varying degrees of linguistic skill — to the point of “2 1/2-year-old human”, which seems incredible. One of them even knaps stone tools, though it’s unclear if this was the result of teaching or not.
Although it’s interesting, I wonder what purpose would be served in teaching apes in general to talk. As the story in Carl Sagan’s Contact goes: monkeys do not talk, because if people heard them, they would immediately be put to work. Since human nature seems far closer to that of the warlike chimpanzee than the peaceful bonobo, I’d think that any more substantial interaction between our species would be even more harmful and opressive than it already has been, given that we’ve driven the great apes almost to extinction.