British Sign Language (BSL) is the first or preferred language of an estimated 70,000 Deaf people in the UK. In March 2003, BSL was recognised by the Government as a language in its own right. BSL is a visual-gestural language, with its own grammar and principles, which are completely different from the grammatical structure of English. Signs, body movements and facial expressions all work together to produce a unique visual language with its own structure and grammar. BSL is different from other sign languages of the world. It is not a visual representation of English.

Only one message can be interpreted at a time so it is important to make sure that only one person speaks or signs at a time. If this does not happen, the interpreter will not be able to work properly and will be placed in the uncomfortable situation of having to interrupt the meeting to request some order.