I love African Greys! Extremely smart birds, and yes, you have to watch everything you say around them.
My sister had a green cheeked Amazon for a few years, and he could whistle the theme to the Lone Ranger (William Tell Overture). He could speak in both English and Spanish. He would sit in his cage and call the dog and the dog would come, it sounded just like her. She had to give the bird away at one point and sent him to some lady on the West Coast that had a breeding program- but right after that she could not contact her to make sure the bird was alright. I often wonder what actually became of him, makes me sad to think that something funny was going on.
They are a big commitment, and they live a very long time, you have to have a plan in place in case something happens to you, just like you do with a child.
Lovely bird, and share more if you can.
"I reject your reality, and substitute my own!" Mythbusters