A businessman was trying to teach his young son to talk flexibly—neither saying yes or no, but remaining ambiguous. "For example," he said, "if someone wanted to borrow food, you could answer, 'I don't know whether we have that or not. Let me have a look, and I will tell you later.'"

The boy kept his father's words in mind, so when a visitor asked if his father was in, the son replied:

"I'm sorry. Some are in, some are not. Let me have a look, and I will tell you later."