Many people assume that sign language is a universal tool that transcends the differences of spoken languages, but this is not true. There are a wide variety of different sign languages spoken around the world, each with different origins and breadth of use. Here is a quick guide to some of the different international sign languages you may encounter.
British Sign Language

Developed in and used in the United Kingdom, British Sign Language has an estimated 150,000 users. The language was developed after the 1760 founding of Great Britain’s first public school for deaf students, although there are reports of a version of British Sign Language being used as far back as 1576.
While the use of British Sign Language is widespread today, it was not recognized by the British government until 2003. Despite the slow uptake from the governing body of the United Kingdom, it is an official language of Scotland.
French Sign Language

French Sign Language, which has about 100,000 users today, was one of the first sign languages to be developed for the modern era, and as such, it influenced many other sign languages. American Sign Language, Russian Sign Language, and even Mexican Sign Language have evolved from French Sign Language.
Charles Michel de l’Épée is often given credit for popularizing French Sign Language and codifying its rules and signs. In 1755 he established the first public school for the hearing impaired in France, which helped French Sign Language establish itself as one of the most influential sign languages in the world.
Brazilian Sign Language

One of the most active sign language communities in the world is found in Brazil, which has developed its own sign language that is so distinct that it is considered an isolate language. Brazilian Sign Language, or Libras, was developed in the late 20th century and was made an official language of Brazil in 2002.
It is unclear just how widespread the use of Brazilian Sign Language is. Official reports estimate that there are 5 million deaf individuals living in Brazil. However, usage statistics report that about 200,000 people use it as their primary method of communication.
American Sign Language

Perhaps the most used sign language in the Western Hemisphere is American Sign Language (ASL). ASL is used in the United States, Canada, certain areas of Southeast Asia, and in West Africa. There are an estimated 200,000 ASL speakers worldwide.
ASL is a descendant of two root sign languages. Like many other modern sign languages, it was influenced by French Sign Language. However, it was also heavily influenced by Martha’s Vineyard Sign Language. Martha’s Vineyard Sign Language was developed on the Massachusetts island Martha’s Vineyard, which had an exceptionally high percentage of deaf individuals. On some parts of the island, one out of every four community members was deaf.
While there are no native Martha’s Vineyard Sign Language speakers left on the island today, the legacy of the language is carried on in ASL.
Chinese Sign Language

There is a lack of data on just how many people utilize Chinese Sign Language, but as the world’s most populous country, there is a good chance it is near the top of the list. However, it is difficult to determine since Chinese schools prefer an oralist approach to teaching deaf children to communicate, which prioritizes lip reading over sign language.
Despite these challenges, Chinese Sign Language has many unique facets, such as signs that replicate written Chinese symbols and multiple dialects. The dominant dialects are regional, one based in the northern region of China around the city of Beijing and the other originating from the southern part of the country near Shanghai.