"Y" is for "Yelling"

We're still hooked on our Dr. Seuss ABC book. Whenever I read the "Y" page, about a little girl yelling, I say "yelling" really loud...you know, so he will understand what yelling means. Today I paused right before the word "yelling", to see if he would fill in the blank, and to my surprise, he did it without hesitation and even used the appropriate volume.