Guardian Focus: Contains material some listeners may find offensive

WARNING: this programme explores the offensive side of the English language. As a result, it contains frequent use of swearing and words to which some listeners may object As the British Library opens a new exhibition on the English language, we explore the use of taboo words. Evolving English: One Language, Many Voices runs until April. Its curator, Jonnie Robinson , looks at how we have changed the way we communicate. We also listen to a potty-mouthed recording from the British Library's archives. Dr Colleen Cotter , senior lecturer in linguistics at Queen Mary University of London, explains why we swear and what we're trying to say by our choice of profanities. The Guardian's readers editor, Chris Elliott , explains why we choose not to use asterisks when printing swear words. Who is protecting the nation's ears? Chris Banatvala from the broadcasting regulator Ofcom tells us what offends the public. Political satire The Thick Of It's 'swearing consultant' Ian Martin discusses why bad language can be funny. What is the ultimate swear word? Peter Silverton , author of Filthy English: The How, Why, When and What of Everyday Swearing gives his verdict. Subscribe to the Guardian's Focus podcast .