This is Zephyr or Zeph, my Congo African Grey parrot, mumbling various phrases, whistling, and talking to my dog, or rather imitating me talking to my dog, boyfriend and rabbit (their nicknames).
He is six years old and remembers even his first words. It always amazes me when he blurts out some phrase he used to favor 4 years ago. But they have amazing memories.
He responds to body language and situations with language too - so it's not always about mimicking, but associating proper words with the right situation. With this video, he's just going through the motions though - he will not speak if I'm in front of him like I said.