This guy goes to a pet shop to buy a parrot. There he sees a parrot with a red string tied to its left leg and a green string tied to it's right leg. He asks the owner the significance of the strings.
“Well， this is a highly trained parrot. If you pull the red string he speaks French； if you pull the green string he speaks German，” replies the shop keeper.
“And what happens if I pull both the strings？” our curious shopper inquires.
“I fall off my perch you fool！！” screeches the parrot.