A linguist and an expert on the development of the English language, David Crystal presents two books that tell us a great deal about English as it is spoken in the 21st century. You Say Potato looks at accents and our different ideas about ‘correct’ pronunciation, while The Disappearing Dictionary features a treasure trove of lost English dialect words such as dabberlick, fubsy and squinch. In David's Book Festival event, he talks to Jenny Niven about his fascinating work. The event was filmed live at the 2015 Edinburgh International Book Festival.