Do you eat mashed potato or mashed potatoes' Are you frowning with your eyebrows or your mouth' Did you need to google mugwump when Boris Johnson laid into Jeremy Corbyn' British and American English may seem similar, but their differences abound. Contentious cultural wars are waged daily, on both sides of the Atlantic. As an American linguist based in Britain, Lynne Murphy brings a wry fish-out-of-water wit and a keen sociological eye to the evolution of these two strands of the same language and how respective speakers perceive one another. In America there is a malady where sufferers are encumbered by a verbal inferiority complex, while on this side of the pond some Brits are gripped by a delusional paranoia that their English is under attack. Murphy puts the mythologies of British and American English to the test, revealing some surprises about how our shared language really works.