Knock Knock!

Lately Tori's been obsessed with knock knock jokes. She's finally learning some new ones, but for a while, the only one she knew was:

knock knock
who's there?
banana
banana who?
knock knock
who's there?
banana
banana who?
knock knock
who's there?
orange
orange who?
orange you glad I didn't say banana?!

I think the point of the joke was lost on her, because she started substituting various words for "orange" that made no sense. So she'd say "apple" and then "apple you glad I didn't say orange". I tried explaining to her that the reason why it works with "orange" is that "orange you glad" sounds like "aren't you glad", but she still didn't really get it. So a few weeks ago she said, "Hey Mom, I figured it out!" and started with the beginning of the same joke. For the last part, she did this:

knock knock
who's there?
grape
grape who?
isn't it grape that I didn't say orange!

It made me laugh that at least she was starting to get the concept of a play on words!