Sign language

Sign languages, also known as signed languages, are special ways of communicating using hand movements and facial expressions instead of spoken words. They are complete languages with their own rules and words, just like spoken languages. Each sign language is unique to a specific place and cannot always be understood by people from other regions, even though there may be some similarities.

These languages developed in communities where deaf and hard of hearing people live, and they are very important for the culture and identity of these communities. While they are mainly used by people who cannot hear well, many hearing people also use sign language, especially those who have family members who are deaf or hard of hearing.

Sign language is different from body language, which is the way people use gestures and expressions to show feelings or thoughts without words. Experts in language study also separate sign languages from other systems, like made-up hand signs for spoken languages or simple signs used at home by families.

The exact number of sign languages in the world is not known, but each country usually has its own. Some countries even have more than one. By 2021, the most used sign language was Indo-Pakistani Sign Language, which is spoken by more people than many spoken languages. Some sign languages have also been officially recognized by laws in their countries.

History

Main article: History of sign language

Groups of people who could not hear have used sign languages for a very long time. One of the oldest written mentions of sign language comes from around the fifth century BC in the writings of Plato's Socrates. He wondered how people would communicate without speaking, suggesting they would use hand movements.

Throughout history, many places developed their own ways of signing. In the Middle Ages, some religious communities in Europe used special hand signs. Later, in the 1500s, explorers found that Indigenous peoples in what is now Texas and northern Mexico already had their own complete sign language.

In 1620, a man named Juan Pablo Bonet wrote a book in Madrid about teaching people who couldn’t speak. He created one of the first systems for using hand shapes to represent letters and words.

Over time, different sign languages developed in many countries. In Britain, people used hand signs for secret messages or to talk with deaf friends. By the 1700s, a British hand sign system had taken its basic shape, and it spread to many places around the world including the United States.

In the 1700s, a Frenchman named Charles-Michel de l'Épée created a hand sign system that is still used in France and North America today. He also started the first school for deaf children in Paris. One of his students, Laurent Clerc, helped start the first school for deaf people in the United States in 1817.

Today, there is also a special sign language called International Sign used at events for deaf people from different countries around the world.

Linguistics

Sign languages have the same capability and complexity as spoken languages. Studying them as part of linguistics shows they have all the basic properties found in any language. This includes duality of patterning, where smaller units combine to form larger meaningful units, and recursion, where grammatical rules can be applied repeatedly.

Unlike mime, signs in sign languages are conventional and often arbitrary, similar to most spoken languages. While iconicity (where signs resemble what they mean) is more common in sign languages, it is not absolute. Sign languages organize basic units into meaningful ones, using parameters like handshape, orientation, location, movement, and non-manual expressions. Both sign and spoken languages share characteristics such as transitoriness, semanticity, arbitrariness, productivity, and cultural transmission.

Common features in many sign languages include classifier constructions, inflection through movement changes, and topic-comment syntax. Sign languages can convey meaning simultaneously using space, two manual articulators, and facial expressions. Today, linguists study sign languages as true languages. However, the category "sign languages" was not added to the Linguistic Bibliography until the 1988 volume.

Relationships with spoken languages

There is a common misunderstanding that sign languages are spoken languages expressed in signs or invented by hearing people. In reality, sign languages develop naturally among deaf communities. As they develop, sign languages sometimes borrow elements from spoken languages, such as using a manual alphabet (fingerspelling) for proper names or concepts without existing signs. However, sign languages are independent and follow their own paths of development. For example, British Sign Language and American Sign Language are quite different, even though the hearing populations in the UK and the US share the same spoken language.

Spatial grammar and simultaneity

Sign languages use the visual medium to their advantage, sometimes using spatial elements like classifiers to show a referent's type, size, shape, movement, or extent. While sign languages can express meaning simultaneously, this is limited by motor constraints and often follows linear sequencing.

Non-manual elements

Sign languages use non-manual elements like facial expressions and body movements to convey prosody, lexical distinction, grammatical structure, and discourse functions. For example, facial expressions can distinguish between signs that look similar manually.

Iconicity

Iconicity, where the form of a sign relates to its meaning, is studied in sign languages. While early linguists doubted its importance, it is now recognized as a feature that varies among sign languages. Iconicity can aid in learning and memory but does not define a language as valid.

Classification

Sign languages can be classified based on how they arise. Home sign is informal and individual, while village sign languages are shared in communities with high deafness rates. Deaf-community sign languages develop where deaf people form their own communities. Speech-taboo languages are gestures used by hearing people, sometimes adopted by the deaf.

Typology

Sign languages vary in word-order typology and tend to be incorporating classifier languages. They also differ in systems for cardinal numbers.

Acquisition

Children exposed to sign language from birth acquire it naturally, similar to hearing children learning spoken language. Research shows that native sign language users perform better in certain tasks and exhibit differences in grammatical morphology.

Written forms

Sign languages lack a traditional written form, but several systems have been developed to represent them, including Stokoe notation, Hamburg Notation System, SignWriting, and others. However, there is no consensus on a widely used written form.

Sign perception

Native signers perceive and categorize handshapes and other elements based on visual experience, influencing how they process and produce signs.

In society

Deaf communities and Deaf culture

Main article: Deaf culture

When there are only a few deaf people in a community, they often form their own special group that is different from the rest of the community. These groups exist all over the world, especially in cities and across whole countries, and they have rich cultures of their own.

One special kind of sign language is Black ASL. It was created in schools for black deaf students during a time when schools were separated by race.

Use of sign languages in hearing communities

Sometimes, in places where many people are deaf, the whole community uses a special sign language. This can happen in small, close-knit villages. Famous examples include:

• Martha's Vineyard Sign Language, United States
• Al-Sayyid Bedouin Sign Language, Israel
• Kata Kolok, Bali
• Adamorobe Sign Language, Ghana
• Yucatec Maya Sign Language, Mexico

In these places, deaf people are usually well accepted and not treated differently.

Many Australian Aboriginal sign languages developed because of special rules about speaking in certain situations, like during sad times or special ceremonies. They were especially well developed among the Warlpiri, Warumungu, Dieri, Kaytetye, Arrernte, and Warlmanpa.

A sign language also developed among tribes of American Indians in the Great Plains of North America before Europeans arrived. It was used to help different tribes talk to each other, and some people still use it today among the Crow, Cheyenne, and Arapaho.

Sign language is also used by people who can hear but have trouble speaking.

Schools and colleges are more and more interested in teaching sign language. In the U.S., many students are choosing to learn American Sign Language as a second language. In New Zealand, after a law was passed in 2006, schools started offering New Zealand Sign Language as a subject for students.

Legal recognition

Main article: Legal recognition of sign languages

Some sign languages have laws that support their use, while others do not. People believe that sign languages should be recognized and supported, not just as a help for people who are deaf, but as the way that whole communities communicate.

Laws about showing sign language on TV and in other places are different in each country. In the United Kingdom, rules were made in 1996 and updated in 2003 to help make sure deaf and blind people could watch TV.

Interpretation

Main article: Language interpretation § Sign language

To help deaf and hearing people talk to each other, sign language interpreters are often used. This needs a lot of work because sign languages have their own special ways of expressing ideas, just like spoken languages.

Interpreters usually change words from one sign language to one spoken language used in the same country, like French Sign Language to spoken French in France, or American Sign Language to spoken English in the U.S. Interpreters who can change words between languages that are not usually paired, like Spanish Sign Language and English, are also available but less common.

Sign language is sometimes shown on TV programs that have talking. The signer usually appears in a corner of the screen, and the show might be smaller so both the signer and the program can be seen. Live sign language interpretation for big events like press conferences is becoming more common.

Technology

One of the first times technology helped deaf people talk to each other was in 1964 at the New York World's Fair, when two deaf people used a special phone to talk. But video calling did not become common until the early 2000s when the Internet had enough speed.

Now, deaf people can talk using video calls, either with special devices made for sign language or with regular video calling services on computers. Some special devices can help make the signing clearer.

Main articles: Video remote interpreting and Video relay service

With new technology, interpreters can be in different places. In video remote interpreting, the interpreter is in one place and talks to a deaf person and a hearing person who are together somewhere else. Video relay service lets a deaf person, an interpreter, and a hearing person all talk to each other even if they are in three different places.

New computer programs are being made that can change videos of sign language into written words.

Sign language is also used in movies. In Brazil, all movies shown in theaters must have a special track in Brazilian Sign Language that can be played on a second screen.

Sign Union flag

The Sign Union flag was designed by Arnaud Balard. It shows the shape of a hand and uses three colors: dark blue for deaf people and humanity, turquoise for sign language, and yellow for hope. The flag is meant to be a welcome symbol for deaf people all over the world.

Language endangerment and extinction

Just like spoken languages, sign languages can also disappear. For example, a sign language used by a small group might be replaced by one used by a larger group. This has almost happened to Hawai'i Sign Language, which is only used by a few older people now. Even well-known sign languages can lose users. Ways are being found to measure how healthy a sign language is.

Extinct sign languages

• Angami Naga Sign Language
• Henniker Sign Language
• Martha's Vineyard Sign Language (MVSL)
• Old French Sign Language (VLSF)
• Old Kentish Sign Language (OKSL)
• Pitta Pitta sign language
• Plateau Sign Language
• Rennellese Sign Language (RSL)
• Sandy River Valley Sign Language
• Warluwarra sign language

Communication systems similar to sign language

Main article: Manually coded language

Some communication systems look like sign languages but are not full sign languages. These systems often develop when people who can hear and people who are Deaf try to talk to each other. They might use signs from a real sign language but follow the rules of spoken language instead. These systems are usually only used to help teach Deaf children how to speak and are not used outside of school.

Main article: Baby sign language

Some parents who can hear teach signs to their young children. This can help because babies' hands grow faster than their mouths, so they can use signs before they can talk. This makes it easier for parents to understand what their baby wants. When the child starts talking, they usually stop using signs. This is different from children who grow up with Deaf parents, who often learn a full sign language just like Deaf children do.

Main article: Home sign

Sometimes, families create their own simple sign systems. For example, if a family has a child who is Deaf and the parents do not know sign language, the child might naturally create signs to talk. These signs help the child share ideas but are not a full language. They are not as complete as real sign languages.

Main article: Great ape language § Primate use of sign language

Scientists have taught some animals, like chimpanzees, gorillas, and orangutans, to use signs to talk with humans. However, this does not mean the animals know a full human language. They only learn some signs or words.

Main article: Origin of language § Gestural theory