An Englishman, a Frenchman, a Spaniard, and a German are all watching a dolphin do some excellent tricks. The dolphin notices that the four gentlemen have a very poor view, so he jumps higher out of the water and calls out, 'Can you all see me now?' And they respond: 'Yes.' 'Oui.' 'Sí.' 'Ja.'
Some marine biologists argued about how best to handle angry dolphins. The were working at cross porpoises.
A linguistics professor says during a lecture that, "In English, a double negative forms a positive. But in some languages, such as Russian, a double negative is still a negative. However, in no language in the world can a double positive form a negative." But then a voice from the back of the room piped up, "Yeah, right."