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 Good Mystery
A mystery-lover takes his place in the theater for opening night, but his seat is way back in the theater, far from the stage. The man calls an usher over and whispers, ''I just love a good mystery, and I have been anxiously anticipating the opening of this play. However, in order to carefully follow the clues and fully enjoy the play, I have to watch a mystery close up. Look how far away I am! If you can get me a better seat, I'll give you a handsome tip.''
The usher nods and says he will be back shortly. Looking forward to a large tip, the usher speaks with his co-workers in the box office, hoping to find some closer tickets. With just three minutes left until curtain, he finds an unused ticket at the Will Call window and snatches it up. Returning to the man in the back of the theater, he whispers, ''Follow me.'' The usher leads the man down to the second row, and proudly points out the empty seat right in the middle. ''Thanks so much,'' says the theatergoer, ''This seat is perfect.'' He then hands the usher a quarter.

The usher looks down at the quarter, leans over and whispers, ''The butler did it in the parlor with the candlestick.''