A lecture about English
A linguistics professor was lecturing to his English 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 voice from the back of the room piped up, "Yeah, right."

A blonde bought an AM radio and it took her a month to find out she could listen to it at night.
A blonde bought an AM radio and it took her a month to find out she could listen to it at night.