Joke of the day :-)

A linguistics professor was lecturing his class one day.

"In English", he said, "A double negative forms a positive. In some languages, though, such as Russian, a double negative is still a negative. However, there is no language wherein a double positive can form a negative."

A loud voice from the back of the room piped up, "Yeah, right."

Pretty cool, eh! From The Telegraph, via aldaily.com