This is one of the most frequently asked questions about deaf communities, and its answer is usually surprising. So how many sign languages are there in the world?
There are over 300, and this figure is a low estimate since some are not yet documented by linguists.
This diversity contradicts intuition. Since signs are made through gestures, they should be understood everywhere. The reality is quite different: two signers from different countries generally do not understand each other spontaneously.
The explanation lies in the origin of these languages. They were not invented to transcribe a spoken language. They are natural languages, spontaneously born within deaf communities, which have evolved like spoken languages: through contact, isolation, and transmission between generations.
One point deserves to be highlighted as it often surprises. Two countries sharing the same spoken language can have totally different sign languages. Conversely, two sign languages separated by thousands of kilometres can be very similar if they share a common historical origin.
The lineages thus follow their own genealogical tree, unrelated to that of spoken languages.
Finally, note that diversity also exists within the same country, with regional variations comparable to the accents and local expressions of a spoken language.
In this article, we detail this count and what explains this diversity.
What are the main sign languages in the world?
Here are the most spoken and documented, classified by geographical area.
North America
ASL, American Sign Language, used in the United States and English-speaking Canada
LSQ, Quebec Sign Language
LSM, Mexican Sign Language
Western Europe
LSF, French Sign Language
BSL, British Sign Language
DGS, German Sign Language
LIS, Italian Sign Language
LSE, Spanish Sign Language
NGT, Dutch Sign Language
VGT and LSFB, the two sign languages of Belgium
DSGS, Swiss-German Sign Language
ÖGS, Austrian Sign Language
LGP, Portuguese Sign Language
ISL, Irish Sign Language
Northern and Eastern Europe
SSL, Swedish Sign Language
NTS, Norwegian Sign Language
DTS, Danish Sign Language
FinSL, Finnish Sign Language
RSL, Russian Sign Language
PJM, Polish Sign Language
Asia
CSL, Chinese Sign Language
JSL, Japanese Sign Language
KSL, Korean Sign Language
IPSL, Indo-Pakistani Sign Language
TSL, Taiwanese Sign Language
VSL, Vietnamese Sign Language
Latin America
Libras, Brazilian Sign Language
LSA, Argentine Sign Language
LSCh, Chilean Sign Language
LSC, Colombian Sign Language
Africa and the Middle East
SASL, South African Sign Language
ArSL, Arabic Sign Languages, varying greatly by country
ISL, Israeli Sign Language
Oceania
Auslan, Australian Sign Language
NZSL, New Zealand Sign Language
Among these languages, IPSL is probably among the most used in the world by the number of speakers, given the population it covers.
The comparison between ASL and BSL remains the most instructive. The United States and the United Kingdom share English, yet their sign languages are mutually incomprehensible. One spells with one hand, the other with two.
Finally, note that some countries have multiple sign languages, like Belgium, while others share a single one beyond their borders.
Why are there so many sign languages?
The answer lies in a fact that many ignore: these languages were not invented. They were born naturally, just like spoken languages.
Everywhere deaf people have been gathered for a long time, a language has spontaneously emerged to meet their need to communicate. These emergences occurred independently of each other, on different continents and at different times.
There is therefore no reason for the signs to resemble each other, no more than the words of one spoken language resemble those of another.
Three factors have then shaped this diversity.
First, geographical isolation. Deaf communities have long lived without international contact, allowing each language to evolve separately for generations.
Then, schools for the deaf, which have played a decisive role. Each institution has been a hub where a language has stabilised and been transmitted, and the lineages between languages often follow the historical relationships between these establishments.
Finally, local culture. The signs reflect realities specific to each society: conventional gestures, everyday objects, shared references, and ways of designating family relationships.
One point needs clarification. These languages are not gestural translations of spoken languages. They have their own grammar, often very different from that of the spoken language of the same country.
Is there an international sign language?
Yes, but it is not a language in its own right. It is a contact system called International Sign, used during meetings between signers from different countries.
The distinction deserves to be understood, as it changes everything.
A language has a stable grammar, a fixed vocabulary, and native speakers who acquire it in childhood. International Sign meets none of these three criteria.
Its vocabulary remains limited and varies according to the participants in the exchange. Its grammar fluctuates, each signer adapting it from their own language. And no one learns it as a mother tongue, as it is always acquired in addition to a national language.
Its functioning relies heavily on iconicity, that is, on signs whose form directly evokes the meaning. Signers combine descriptive gestures, mimes, and borrowings from their respective languages.
Its use is concentrated in specific contexts: international congresses, sports meetings, representative organisation meetings, and informal exchanges between deaf travellers.
A structural limit deserves to be noted. International Sign works for concrete and factual exchanges, much less for abstract or nuanced conversations.
One last point is the subject of recurring criticism within the deaf community: this system remains strongly influenced by Western languages, which disadvantages signers from other regions of the world.
Do sign languages vary within a country?
Yes, and these variations are as marked as the accents and regional expressions of a spoken language.
The same concept can be signed differently from one city to another, and these differences have a name: regional variations.
They mainly affect everyday vocabulary. Colours, days of the week, food, and school vocabulary are among the most variable. However, grammar remains stable across the territory, preserving mutual understanding.
Three factors explain this internal diversity.
First, schools for the deaf, and this is the main historical factor. Each establishment has been a linguistic hub where signs have been locally fixed before spreading to the surrounding region.
Then, generations. Older signers and young people do not always use the same signs, particularly in technological or social vocabulary that evolves rapidly.
Finally, local communities, each developing its own usages and expressions.
A reassuring point for learners: these variations do not constitute an obstacle. Signers naturally adapt and ask for clarification when a sign is unknown to them.
A practical consequence deserves to be known. If you notice that a sign differs from the one you were taught, do not correct your interlocutor. Observe the usages around you and adapt.
Conclusion: a diversity comparable to spoken languages
There are over 300 sign languages in the world, and this figure remains a low estimate since some are not yet documented.
First, remember what explains this diversity. These languages were not invented to transcribe a spoken language. They were born naturally within deaf communities, independently of each other, on different continents and at different times.
There was therefore no reason for them to resemble each other.
Then remember the point that surprises the most. Two countries sharing the same spoken language can have mutually incomprehensible sign languages. Conversely, two languages separated by thousands of kilometres can be very similar if they share a common historical origin.
The lineages follow their own genealogical tree, unrelated to that of spoken languages.
Regarding International Sign, treat it for what it is. A useful contact system during international meetings, but not a complete language: limited vocabulary, fluctuating grammar, and no native speakers.
Finally, note that diversity also exists within the same country, with regional variations mainly stemming from the history of schools for the deaf.
What should be remembered fundamentally goes beyond the simple count. Sign languages are natural languages in their own right, with their own grammar, history, and evolution. Their diversity is not a lack of organisation, it is the very proof of their linguistic authenticity.
No living language is universal, and these are no exception.
