Sign languages are forms of communication that use combinations
of hand shapes, the orientation and movement of the hands, arms or body,
and facial expressions to convey everything that spoken languages can
convey. Manual alphabets or fingerspelling is also used to spell out
words and names for which there are no signs.
Sign languages are used mainly by people who are deaf or hard of hearing,
and also by their families, friends and others who have regular contact
with them. However not all deaf people use sign languages - some rely on
lip reading and speech.
There of hundreds of sign languages around the world, most of which
are so different as to be mutually unintelligible. The most widely used
sign language is probably American Sign Language (ASL), which is
used is the USA, Canada, parts of Mexico and, with modifications, in quite
a few other countries in Central America, Asia and Africa. ASL developed
from Old French Sign Language and as a result, has little in common with
British Sign Language (BSL) and the two languages are mutually unintelligible.
A sign language known as International Sign, originally Gestuno,
has developed for use mainly at international Deaf events such as
the Deaflympics and meetings of the World Federation of the Deaf.
It enables people from different deaf communities to communicate
with one another.
Sign languages in writing
A number of systems have been developed for representing sign languages
in written form. These include HamNoSys (the Hamburg Notational System)
and SignWriting, both of which can be used
for any sign language, and Stokoe Notation, a system for representing
ASL in writing developed by William Stokoe in the 1960s.