American Sign Language
American Sign Language is the language used by the majority of Deaf people in the United States and much of Canada. It is a visual/gestural language which has unique grammatical, lexical, and other linguistic features. It is not a manual code of English.
An interpreter must be able to listen to another person's words, inflections and intent and simultaneously render them into the visual language of signs using the mode of communication preferred by the deaf consumer. The interpreter must also be able to comprehend the signs, inflections and intent of the deaf consumer and simultaneously speak them in articulate, appropriate English. They must understand the cultures in which they work and apply that knowledge to promote effective cross-cultural communications.