Overheard conversation

(Trevor and Sydney lying on the floor of Trevor's room, looking at a book)
SYDNEY: (pointing to a picture of a penguin) What's dat?
TREVOR: That's a penguin.
SYDNEY: No, dat's a duck.
TREVOR: ...That's a penguin.
SYDNEY: No, Treber, dat's not penguin. Dat's a duck.
TREVOR: That's a penguin.
SYDNEY: No, dat's a duck.
TREVOR: (Patiently)That's a picture of a penguin.
SYDNEY: (Earnestly, with much sincerity and sorrow that the poor boy is so confused) No, Treber, dat's not penguin... Dat's a duck. (Turns page. Pointing again.) What's dat?
TREVOR: (Taking the middle ground) That's a bird.
SYDNEY: (Earnestly, sadly) No, Treber, dat's not a bird, dat's a goose.