Linguistics

This joke from growabrain speaks to my family:

"A linguistics professor was lecturing his class. 'In English,' he said, 'a double negative forms a positive. However, in some languages, such as Russian, a double negative remains a negative. But there isn't a single language, not one, in which a double positive can express a negative.' A voice from the back of the room piped up, 'Yeah, right.'"