There are two types of African Greys, Congo's and Timnehs. Congos are bit bigger, lighter grey and they have fully black beaks with bright red tail feathers. Timnehs are said to be easier going with Congo's being more emotional.
They can mimic sounds throughout the house including phones, microwave and door lock beeps. The cat's meow. The dog's bark. What is most impressive is talking. They can talk in different peoples voices and accents. All have the ability to talk and how much they talk can have to do with both their personality as well as how much time you spend with them. The more you pay attention to them the more personality you'll get back from them.