British Sign Language (BSL) is the primary from of communication for around 50,000 people in the UK, while speech recognition is now advanced to the point of being commercially available there is relatively little being done for the deaf community.

BSL is a complex visual-spatial language that is used by the Deaf community in the UK. It is a linguistically complete, natural language. It is the native language of many Deaf men and women, as well as some hearing children born into Deaf families. It shares no grammatical similarities to English and should not be considered in any way to be a broken, mimed, or gestural form of English. In terms of syntax, for example, BSL has a topic-comment syntax, while English uses Subject-Verb-Object.

Some people have described BSL and other sign languages as "gestural" or "manual" languages. This is not correct because hand gestures are only one component of BSL. Facial features such as eyebrow motion and lip-mouth movements are also significant in BSL as they form a crucial part of the grammatical system. In addition, BSL makes use of the space surrounding the signer to describe places and persons that are not present.

Sign languages develop specific to their communities and are not universal. For example, BSL is totally different from American Sign Language even though both countries speak English.

It should also be noted that BSL has a very complex grammar. Unlike spoken languages where there is just one serial stream of phonemes, sign languages can have multiple things going on at the same time. This multiple segmentation creates an interesting addition to the challenges already facing SLR researchers. BSL has its own morphology (rules for the creation of words), phonetics (rules for handshapes), and grammar that are very unlike those found in spoken languages.

You can find out more about BSL from The Council for the Advancement of Communication with Deaf People (CACDP) or The Royal National Institute for Deaf People (RNID)