Why sign languages are far more than just spoken words expressed through gestures
Many believe sign languages are merely manual versions of spoken tongues, but the reality is much more complex. These are independent, natural languages with their own unique grammars, capable of expressing intricate ideas through simultaneous movements, facial expressions, and spatial arrangements that spoken words simply cannot replicate.
Contrary to popular belief, sign languages are not invented by hearing teachers or are simply coded versions of spoken languages. Instead, they are natural languages developed by Deaf communities. While figures like Abbé de l'Ép려는 or Thomas Hopkins Gallaudet are often credited as 'inventors,' they were actually educators. True sign languages, like American Sign Language (ASL) or British Sign Language (BSL), possess their own distinct syntax and lexicon. In fact, ASL shares more structural similarities with spoken Japanese than it does with English.
The linguistic complexity of signing relies on a visual-manual modality. Unlike the linear nature of speech, sign languages can utilize simultaneous expression. This is achieved through five key parameters: handshape, orientation, location, movement, and non-manual expression. Non-manual markers—such as eyebrow position, head tilts, or mouth movements—are essential for grammar. For example, in ASL, a forward head tilt and raised eyebrows are used to signal yes/no questions, while specific mouth shapes can distinguish between different meanings.
The diversity of these languages is vast and often undocumented. While the 2021 Ethnologue edition lists 150 sign languages, the SIGN-HUB Atlas suggests there are over 200. This diversity means that sign languages are rarely mutually intelligible; a signer from one region may not understand another. Even within a single country, multiple variants can exist, as seen in South Africa, where two major educational institutions led to the development of two distinct variants of the national sign language.
Source: Sign language
