Teacher going round her class asking them about the books they are reading...
"Johnny, what's your book about?"
"I'm reading a book about a brum-brum"
"No, Johnny, we don't say brum-brum, we say car. Now Alfie, what's your book about?"
"It's about a choo-choo"
"No,dear, we say train, not choo-choo. Now I only want to hear you use grown-up words for things. Sally, what are you reading?"
"I'm reading a book about Winnie the Shit"