In an talk on Edge.org [4], Dr. Pepperberg [5] told of an effort to teach the parrot about phonemes using colored tokens marked with letter combinations like sh and ch.

“What sound is green?”

“Ssshh,” Alex answered correctly, and then demanded a nut. Instead he got another question.

“What sound is orange?”

“Ch.”

“Good bird!”

“Want a nut!” Alex demanded. The interview was over. “Want a nut!” he repeated. “Nnn ... uh ... tuh.”

Dr. Pepperberg was flabbergasted. “Not only could you imagine him thinking, ‘Hey, stupid, do I have to spell it for you?’ ” she said. “This was in a sense his way of saying to us, ‘I know where you’re headed! Let’s get on with it.’ ”

She is quick to concede the impossibility of proving that the bird was actually verbalizing its internal deliberations. Only Alex knew for sure. ... [3]