People outside the deaf community may not know that the regional variations found in spoken language also exist in sign language. This variation is the subject of the current BSL Corpus Project, led by the team at the UCL Deafness, Cognition and Language Research Centre (DCAL). Dr Adam Schembri, Senior Research Fellow and Project Director, explains what this research is telling us about the history of a language that, like every other, is continually changing.