Every two weeks another language becomes extinct and, according to UNESCO, more than 2400 languages spoken today are endangered and will probably vanish by the end of the century. In this edition of Word of Mouth Chris Ledgard meets some of those who are dedicating their lives to maintaining global linguistic diversity. These include Dr Mark Turin, the founder of the Oral Literature Project in Cambridge who works with Thangmi speakers in a remote region of Nepal; Dr Stephen Leonard who is preparing to spend a year in Northern Greenland with a community whose language is threatened as an indirect consequence of global warming; and Dr Julia Sallabank who is working to preserve Guernesiais, a language unique to the island of Guernsey. According to the 2001 census, it was spoken by just 2% of the population. Producer Paul Dodgson.