It is noteworthy to remember that both species need to benefit from the relationship to be symbiotic.
It all depends what you mean with 'easy'. Most parrots pick up a few words without teaching them, even in an aviary. Mynah birds CAN make the best talkers but they are not as clever as an African Grey Parrot which can related it's words to visual objects. Not an easy thing to do for a bird. The Conures are well known for learning long passages of songs, both singing and whistling.