When we considered the process of language acquisition, we concentrated on the fact that what is naturally acquired by most children is speech. Yet this is not the only way that a first language can be acquired. Just as most children of English-speaking or Spanish-speaking parents naturally acquire English or Spanish at a very early age, so the deaf children of deaf parents naturally acquire Sign (or sign language). Later in life, as Oliver Sacks discovered, they may even use Sign when they ‘talk’ in their sleep. If those children grow up in American homes, they will typically acquire American Sign Language, also known as Ameslan or ASL, as their version of Sign. With a signing population of at least half a million, and perhaps as many as two million, ASL is one of the most widely used non-English languages in the United States. The size of this population is quite remarkable since, until relatively recently, the use of ASL was discouraged in most educational institutions for the deaf.