This is a study about cats but it mentions the fact that parrots understand some human words but, in my personal opinion, parrots understand much more than 'some' words, they understand A HUGE LOT of them AND they know their name AND they come or answer when you call them. As to cats, all of mine know their name and they not only come when I call them, they also come when Davy Redbelly calls them too - which he does when he sees me coming with their food plates
https://www.sciencedaily.com/releases/2 ... 101120.htm