Insights from Sign Language
We now consider some of the linguistic properties of American Sign Language (ASL). Unlike speech, signs are expressed in visual or spatial from. This enables us to examine the extent to which the grammatical concepts we have just considered generalize to language in a visual modality.
American Sign Language is sharply distinguished from manual forms of English that translate English sounds into signs. That best known is fingerspelling, which, as the name implies, translates English language. In contrast, ASL is independent of English and derived from French Sign Language. Although in the past ASL was regarded as mere pantomime or grammatically deficient in various ways, several decades of scholarly research on ASL have put these ideas to rest.