BANZSL

British, Australian and New Zealand Sign Language (BANZSL) is the language of which British Sign Language (BSL), Auslan and New Zealand Sign Language (NZSL) may be considered dialects. These three languages may be considered dialects of a single language (BANZSL) due to their use of the same grammar and manual alphabet and the high degree of lexical overlap. The term BANZSL was coined by Trevor Johnston and Adam Schembri.

BSL, Auslan and NZSL all have their roots in a deaf sign language used in Britain during the 19th century.

American Sign Language and BANZSL are unrelated sign languages. However, there is still significant overlap in vocabulary, probably due largely to relatively recent borrowing of lexicon by signers of all three dialects of BANZSL, with many younger signers unaware which signs are recent imports.

Between Auslan, BSL and NZSL, 82% of signs are identical (per Swadesh lists). When considering identical as well as similar or related signs there are 98% cognate signs between the languages. By comparison, ASL and BANZSL have only 31% signs identical, or 44% cognate.

According to Henri Wittmann (1991), Swedish Sign Language also descends from BSL. From Swedish SL arose Portuguese Sign Language and Finnish Sign Language, the latter with local admixture; Danish Sign Language is largely mutually intelligible with Swedish SL, though Wittmann places it in the French Sign Language family.

Anderson (1979) instead suggested that Swedish Sign, German Sign and British Sign share one origin in a "North-West European" sign language.

Languages

 * BSL (sign attested from 1644 may not be BSL), with approximately 151,000 users
 * Australian SL (1860. ASL and ISL influences), with approximately 10 000 users
 * Papua New Guinea Sign Language (c. 1990), which is a creole formed with Auslan, used by 30,000 people
 * New Zealand SL (1800s), used by approximately 20,000 people
 * Northern Ireland SL (19th century - with American Sign Language and Irish Sign Language influences)
 * South African SL (somewhere between 1846 & 1881), used by perhaps 235,000 people
 * Maritime SL (c. 1860), with perhaps 100 extant users
 * ? Swedish Sign Language family (1800)
 * Swedish Sign Language (1800)
 * Finnish SL (1850s, with local admixture)
 * Finland-Swedish SL (1850s, a middle form between Finnish and Swedish SL)
 * Eritrean Sign (1955, with much local admixture)
 * Portuguese SL (1823)
 * Cape Verdian Sign (1990s, with local admixture)