My Gracie-Mae is very smart I think
She tries to say some phrases like"good girl" and "pretty girl" but she is much better at imitating noises she hears around the house. She does a dead on impersonation of the cell phone, microwave, washing machine, vacuum cleaner and the computer's opening beep
She loves to chirp and sing all day long. I've never tried to teach her words or phrases, she has done it completly on her own.
Good luck on your quest for a new budgie!