An English professor was telling his class that a double negative makes a positive, but there was no case in which a double positive creates a negative.
From the back of the room a Physics professor said, "Yeah, yeah."
In grammar you shouldn’t do double negatives.
It’s a no no.
Watch your grammar please!
The double negative is a complete no no!
Professor told a joke worthy of this subreddit today.
In my computer science course, my very old professor busts this out during a discussion of logic:
"I went to a logic conference once, and the lecturer said, 'it's interesting that a double negative gives you a positive, isn't it? I mean, a double positive doesn't give you a negative.'
Someone from the back of the room scoffed and went, 'yeah, yeah.'"
Half the class chuckled, half the class groaned.
