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."

Actual Answer from a Medical Student
While making his rounds, a doctor points out an x-ray to a group of medical students.

�As you can see,� he says, �the patient limps because his left fibula and tibia are radically arched.�

The doctor turns to one of the students and asks, �What would you do in a case like this?�

�Well,� ponders the student, �I suppose I�d limp, too.�