Many of us have probably heard a parrot say, "Polly Want a Cracker?" on television or in a movie. Parrots are able to produce sounds resembling human speech, barking dogs and even vacuum cleaners. African grey parrots are even able to generate new thoughts. The question is whether these sounds that parrot makes are language or not.
Parrots cannot distinguish between the "a" and "i" sounds. How would they be able to communicate with or like us without distinguishing between these sounds? The answer is that what we call talking parrots are really only parrots mimicking sounds. The speech that is coming out of parrots is due to repetitions and not from actual language comprehension.
The grey parrot's speech is better because they have far greater mental capabilities than other parrot species. This allows them to generate some new thoughts. Now, let's not get excited about thinking that a person could have a grey parrot as a good pet and have meaningful conversations with it. The grey parrots' speech is also due to repetition, and they are not recommended as pets because they are in need of a constant companion, which would make them rather annoying.
I believe that the parrots may use language when they talk like humans, but there is no comprehension of what they are saying. Bringing up a commonly used psychology concept, operant conditioning is more than likely used to get the parrots to mimic the human sounds.
Video of Talking Parrot: