A 3rd grade girl came home from school. She was very happy, and her Mum noticed this. Mum asked, "What makes you so happy today?" The girl said, "Mum, we learned how to make babies in school today!"
Thinking that 3rd grade was a bit early for that, she asked her daughter to tell her how.
"It's easy, Mum -- you just drop the y, and add ies," the daughter said.