It is said African Greys have a brain that rivals a five year old human. One researcher bought a grey parrot from a pet store at random and named him Alex. The researcher and her assistants continued to teach Alex concepts and many were after somebody said to her “Well, yeah, he can do (x) but he can’t do (y)” and so she would teach it (y). Alex learned things like colors, shapes, emotion words and sentence structure.
He also proved to understand what he was saying. He might tell someone “Want cookie” and the assistant might say “Don’t have cookie. Have cracker.” and Alex would reply “Don’t want cracker. Want cookie.”
It’s chronicled in a book called “Alex and Me”. Fascinating read for any bird lovers or behaviorists.
There’s a YouTube video where an African Gray is, among other things, ordering Alexa, “Alexa, all lights on” and “Alexa, all lights off”. It’s kind of freaky.