ASL is far from the only sign language. Researchers have identified more than 130 distinct sign languages worldwide, and ongoing surveys suggest the actual number may exceed 400. Every country with a sizable Deaf community has developed its own sign language, and many countries have several. Sign languages are full, natural languages with their own grammar, vocabulary, and regional dialects, and they don’t map neatly onto the spoken languages around them.
Why Sign Languages Don’t Follow Spoken Languages
One of the biggest misconceptions is that sign languages are simply gestured versions of spoken languages. If that were true, the United States, the United Kingdom, and Australia would all share one sign language since they all speak English. They don’t. American Sign Language, British Sign Language, and Australian Sign Language (Auslan) are three separate languages, and ASL and BSL share only about 30% of their signs. Even the alphabet is different: ASL uses a one-handed fingerspelling system, while BSL uses two hands.
This makes more sense once you understand how these languages developed historically. Sign languages evolved within Deaf communities, shaped by the schools, social clubs, and families where deaf people interacted. Spoken language in the surrounding hearing population had little influence on the grammar or vocabulary that emerged.
Sign Language Families
Just like spoken languages have family trees, sign languages do too. ASL belongs to the Francosign family, which traces back to Old French Sign Language. In 1817, Thomas Gallaudet and Laurent Clerc, a deaf educator from France, founded the American School for the Deaf. Clerc taught using French Sign Language, and as his signs blended with the local signs already in use among American deaf communities, ASL was born. Other members of the Francosign family include Dutch, French, Flemish, French-Belgian, and Italian Sign Languages.
British Sign Language sits in a completely different family called BANZSL (British, Australian, and New Zealand Sign Language). This group evolved from Old British Sign Language and includes Auslan, New Zealand Sign Language, South African Sign Language, and several others. Members of the BANZSL family retain some mutual intelligibility with each other, meaning a BSL signer and an Auslan signer can follow parts of each other’s conversations. But a BSL signer and an ASL signer would struggle significantly, despite both coming from English-speaking countries.
Variation Within a Single Sign Language
Even within ASL, there isn’t one uniform way of signing. Regional dialects exist, and one of the most well-documented is Black American Sign Language (Black ASL). It emerged because of the history of racial segregation in American deaf education. Black deaf students attended separate schools through much of the 20th century, and their signing developed distinctive features in those communities. When schools were integrated in the late 1960s, Black deaf students transferring to formerly white schools found the signing noticeably different, sometimes to the point of being challenging to follow in classrooms. Black ASL remains a living variety of the language today, used in families, social settings, and among friends.
Protactile: A Language Built on Touch
Some sign languages don’t use vision at all. Protactile, developed by DeafBlind adults over the past two decades, is a fully tactile language based on touch, using placement, motion, and pressure on the body. Before protactile emerged, DeafBlind people often communicated through chains of interpreters, even when talking to each other. One DeafBlind person has described that older method as “communicating through code” that felt impersonal and awkward.
Starting around 2007, the DeafBlind community began developing direct person-to-person communication through physical contact. In protactile conversation, people place their hands on the bodies of those expressing themselves, and listeners give feedback by tapping on arms or legs. Unlike ASL, which relies on visual signs made in the space around the body, protactile requires two people in physical contact to exist. It conveys spatial and descriptive information through touch that simply isn’t available in a visual sign language. Researchers at Gallaudet University are now studying how DeafBlind children acquire protactile from DeafBlind adults.
International Sign
Given all this diversity, you might wonder how deaf people from different countries communicate with each other. The answer is International Sign, a contact system used at international conferences, Deaf sporting events, and meetings of organizations like the World Federation of the Deaf. It draws on elements from multiple national sign languages, and fluent users treat it as a real communication option alongside their native sign language.
That said, International Sign is not quite a full language in the traditional sense. It has no native speakers, since no children grow up learning it as a first language. Its level of standardization is lower than any national sign language, and it shifts depending on the language backgrounds of the people using it. Most experts describe it as something “language-like,” a form of contact signing rather than a true standalone language. Think of it as comparable to a sophisticated pidgin that gets the job done in international settings but lacks the depth and daily-life coverage of a natural sign language.
Legal Recognition Around the World
About 82 countries, roughly 42% of all nations, have passed legislation officially recognizing their national sign languages. This kind of legal recognition can affect everything from whether schools offer instruction in sign language to whether government services provide sign language interpreters. The fact that countries recognize their own distinct sign languages, not ASL, underscores just how many separate languages exist.
Every sign language has its own grammar, its own way of building sentences, and its own cultural context. They share a common foundation in that all sign languages use the same basic building blocks: handshape, palm orientation, movement, location on or near the body, and facial expressions or body movements that convey grammatical meaning. But how each language combines those elements is as varied as how spoken languages use sounds to build words and sentences. ASL is one rich, complex language among hundreds.