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."

An old rabbi is talking with one of his friends...
An old rabbi is talking with one of his friends and says with a warm smile, "I gladdened seven hearts today." "Seven hearts?" asks the friend. "How did you do that?" The rabbi strokes his beard and replies, "I performed three marriages." The friend looks at him quizically."Seven?" he asks. "I could understand six, but..." "What do you think" says the rabbi, "that I do this for free?"