The shadda is the key difference between a pigeon (hamam) and a bathroom (hammam). Be careful, our professor advised, that you don't ask a waiter, 'Excuse me, where is the pigeon?'-or, conversely, order a roasted toilet . . . If you've ever studied a foreign language, you know what happens when you first truly and clearly communicate with another person. As Zora O'Neill recalls, you feel like a magician. If that foreign language is Arabic, you just...