Parrots are able to mimic human speech due to their unique vocal anatomy. They have a specialized vocal organ called the syrinx, located at the base of their trachea, which allows them to produce a wide range of sounds. Parrots are also highly social animals that learn by imitating the sounds they hear in their environment, including human speech. With practice and exposure to human speech patterns, parrots can learn to mimic words and phrases with surprising accuracy.