I had a cockatiel, Sophie I taught how to talk and she had lots of words she could say, and would turn phrases around, Vet. told me there is only about 5% chance female birds that can be taught to talk. I had taught her several whistles also. I had her 5 yr.s and she loved to dance. For some reason her legs got paralyzed and Vet. and bird specialist did not know why. I had to have her put down, about killed me, she was still very alert and not sick. I love ineracting with the birds. Really easier than dogs or cats. She was a very smart bird.
I have a male cockatiel now, Suky and I haven't heard him talk in a long time. He said a few words, in a very soft voice. When he is uncovered in the mornings he hollars for me to watch him dance. He is so happy. I have tried getting him to talk, to no avail. Maybe when I retire in June.
My bird have to stay in a cage as I have 4 housecats and 2 toy poodles, who would go after him in a New York minute if given half a chance.