(The following text is quoted from the website of the British Deaf Association, www.bda.org.uk)

Contrary to popular belief, Sign Language is not international. Sign languages evolve wherever there are Deaf people, and they show all the variation you would expect form different spoken languages.

They are not derived from spoken language of a country. Thus, although in Great Britain, Ireland and the United States the main spoken language is English, all three have entirely separate sign languages.

As with spoken languages, a sign language can evolve from a parent sign language and therefore show affinities. For instance, due to historical and political links, Australian Sign Language and modern BSL [British Sign Language] share a common ancestor, and there are similarities between the two.

American Sign Language (ASL) bears a resemblance to French Sign Language (LSF) because Laurent Clerc introduced the "methodical sign system" developed by the Abe Del'Epee in eighteenth century France into American Deaf education. There are also the regional dialects and "accents" which are present in every language.

There is a collection of internationally accepted signs - Gestuno - which is sometimes used in the course of international meetings of Deaf people.

In 1988 The European Parliament passed a Resolution on Sign Languages, proposing that every member country recognise its own national Sign Language as the official language of Deaf people in that country.