I laughed so hard I cried

This morning Grant asked me what a sentence was. He has been reading "The Boxcar Children" so I pulled out the book and gave him an example of a sentence. I was showing him that when you get to a period it is the end of the sentence. Then I showed him a sentence with a question mark and an exclamation point. The sentence with the exclamation point said, "And there's our little house!" So I said it with the inflection if there was a period vs. an exclamation point and Grant said, "I get it! When it was a period they were sad because they wanted a big house with a swimming pool."