As I was lying down with her in bed last night going through her 'sight words':
Me: What does a-s spell?
Jenna: A-S....(big eyes) That's a bad word.
Me: No it's not. What's it spell?
Jenna: Ass is a bad word mom.
Me: hahahaha! It spells "azz."
Jenna: Well, ass really isn't a bad word. But we call asses 'donkeys.' Why is ass a bad word?
Me: Well, it's just not nice to call someone an 'ass.'
Jenna: Why are stupid, heck, and shit bad words?
Me: (laughing) 'stupid' and 'heck' really aren't bad words--they're just not nice to say. 'Shit' IS a bad word, but I don't know why. Somehow, over time, it just became a bad word.
Jenna: Can I say 'heck'?
Me: yeah, you can say 'heck.' But not 'shit.'