A linguistics professor was lecturing his class. “In English,” he explained, “a double negative forms a positive. In some languages, such as Russian, a double negative is still a negative. However, there is no language in which a double positive can form a negative.” A voice from the back of the room piped up, “Yeah, right.”
一位語言學教授正在給學生講課。他解釋說:“在英語里,雙重否定構成肯定。在別的語言中,比如俄語,雙重否定還是否定。然而,沒有一種語言可以用雙重肯定構成否定。”這時候,從教室的后面蹦出一個聲音:“是啊,對!”