Referential Communication with an African Grey Parrot: "Alex has learned over 40 object labels: paper, key, nut, wood, wheat, truck, hide (rawhide chips), peg wood (clothes pins), grain, cork, corn, walnut, block, box, showah (shower), banana, pasta, gym, cracker, scraper (nail file), popcorn, chain, kiwi, shoulder, rock (a lava stone beak conditioner), carrot, gravel, cup, citrus, back, chair, chalk, water, nail, grape, grate, treat, cherry, wool, green bean, and banerry (apple). We have tentative evidence for labels such as bread and jacks. He has functional use of 'no', phrases such as 'come here', 'I want X', and 'Wanna go Y' where X and Y are appropriate labels for objects or locations."