From wow-david: My parrot has a vague understanding of the word "no." He knows to stop doing what he's doing when he hears it, and he knows how to say it. He knows it's a word that is used when he's doing something he shouldn't be doing. However, being told "no" doesn't make him stop doing it in future. If he's ever out of my sight or if I'm not paying attention, I know exactly when he's doing something bad. Because he says "no" to himself as he does it.
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