I just wanted to say hello and share some things about "Bird". I've had "Bird" my quaker for 2 and a half years. In that time he has picked up sounds and one word which is "Bird" In that time he has been pretty mellow and kinda a closet talker. He hardly ever interacted with talking back to me. So...Just the other morning after I came home from work I went over to him and said hello, and then I made some noises and bobbed my head up and down. As soon as I did that it was like a light came on. He came out of his shell! He started talking to me a dancing and carrying on, it was sooooo exciting! The day before that I was on Youtube and there was a man on there that had an Aferican Gray and he said that we need to talk to the bird, not at the bird, which will help them learn to talk. That is what I was trying that morning...and it worked! Within 3 days bird is already saying Hello, and mimicing about 4 other sounds! 
Well along with good news comes bad news...He has kinda turned into a naughty bird! If I put my finger up to the cage he lunges at it and really trys to bite me. Which he has never done except when I had a furry triangle bed that he would go into, so I got rid of it over a year ago, and His lunging and trying to bite stopped. It's like he has split personalities. If he is on the right side of his cage sitting there quiet I can reach in and take him out. But as soon as he gets into the other personality forget it, he will bite me. 
And this is when he goes to the center of his cage? Hummm...I don't get it. Is he now being protective over his cage or what? Any idea as to why all of the sudden he is interacting with me? Even though he is being naughty? Ooh and also after he comes after me he backs up talking and bobbing his head, almost like he is back talking me. He seams happy though... I don't get it. Any ideas? 