Dudley's like that too. He may not be much of a talker, but he seems to just,now how to respond. He nods accordingly, and has his own way of saying "no" accordingly. He's a smart bird, alright.
Though I think it takes a real close connection to have a bird that knows just how to participate in a conversation, like that. Lucy's pretty close. She responds, but not in way I would always want her to.

(hence when she offered me a pellet when I said they would "help me with my headache")