It is impressive. The difference with parrots is they can attribute meaning to to words and sounds, combine words and even understand the significance of order words. They even can create their own words. For instance the African grey that we had in our family would make a friction noise when things where moved. She could ask for water or make a water noise. She knew goodnight nellie but no one ever taught her to say goodnight paul. She understood names. Another major intelligence of parrots that often gets overlooked is manipulation but that is one or their major intelligences. They like to figure things out; how to break out, how to get at food.