Are Signed Languages “Real” Languages?
Yes, signed languages are naturally-evolved, non-invented real languages. There is the serious scholarly hypothesis that they may have existed since the onset of spoken languages and, crucially, co-evolved with them. Like spoken language, signed languages are not universal. Many wholly autonomous natural signed languages are used within distinct Deaf cultures around the world. Signed languages are not the signed counterpart of the majority spoken language.For example, the signed language used in Quebec among culturally French Deaf people, called Langue des signes Québécose (or LSQ) and the signed language used by Deaf people in France (FSL), constitute distinct languages and two Deaf people within these respective French cultures would need an interpreter to communicate. This is also true of the signed languages used by cultural English Deaf persons in the United States of America and Canada, called American Sign Language (or ASL), and the Deaf people in Britain who use British Sign Language (BSL), and elsewhere around the world.
American Sign Language is a Real Language
Over 40 years of intensive research by Linguists, Psychologists, Psycholinguists, and Cognitive Neuroscientists, have demonstrated that the signed languages of the world in general, and American Sign Language (ASL) in particular, are real languages. They possess the identical levels of language organization found in all spoken languages: specifically, the Phonological (or sub-lexical), Morphological, Semantic, and Syntactic levels of language organization. American Sign Language, and the other signed languages studied intensely around the world, also convey the full semantic and grammatical expressive range as any spoken language, and they possess similar discourse (or conversational) and pragmatic (or language use) rules–all of which were previously thought to be exclusive to spoken languages.
What is Not a Real Language?
In educational and some other contexts, there are hand codes that have been invented to mirror the structure of a specific spoken language (for example, “Signed English,” or “Signing Exact English,” for spoken English, and “Signed French” for spoken French, and the like).
In educational contexts, for example, Signed English has been used as a teaching method, whereupon the goal is to sign and to speak at the same time. This method has been sometimes referred to as “Simcom” (Simultaneous Communication) and/or “Total Communication.” However, and importantly, such hybrid systems used in Simcom and/or Total Communication neither fully represent the natural signed language (e.g., ASL) nor fully represent the natural spoken language (e.g., English; see, for example, the classic empirical study by Marmor & Petitto, 1979, Sign Language Studies, and many other studies on this topic since). Unlike naturally-evolved signed languages, these are indeed invented codes. Like Morse Code, they are not natural languages–and there are no communities of Deaf people anywhere in the world that that use these invented codes outside of restricted pedagogic contexts.