Although some parrots have been known to learn to speak as many as 50 words, the fact is that parrots are excellent mimics. When they speak, they are really only mimicking words and do not understand what they are saying. Don’t be fooled by the parrot who shrieks “Hello” when you come in, it might say the same thing when you leave! And the parrot who says “Polly wants a cracker” is not telling you it is hungry.
With careful training, parrots can be trained to speak words, sing, and whistle. But they are not speaking in the sense we know it. They are just making a sound they once heard, a sound which has no connection to their inner feeling. They are not using speech to communicate.
While parrots are good mimics, other birds, such as the myna bird and the crow, can be taught human sounds too.
Interestingly, many other birds who do not imitate human sounds can imitate the sounds of other birds. Mockingbirds got their name because of their mimicry powers. Some baby birds, raised with species of birds different from their own, can make sounds just like those other birds.
The calls and songs and different sound patterns of birds in the wild serve another purpose, communication. There are danger calls, alarm calls, food calls, mating calls, and territorial calls.
The most talkative parrot on record, an African gray parrot belonging to a London family, had a vocabulary of almost 1,000 words!