It is said to be the most frequently spoken (or typed) word on the planet, more common than an infant's first word ma or the ever-present beverage Coke. It was even the first word spoken on the moon. It is ""OK""-- the most ubiquitous and invisible of American expressions, one used countless times every day. Yet few of us know the secret history of OK--how it was coined, what it stood for, and the amazing extent of its influence. Allan Metcalf, a renowned popular writer on language, here traces the evolution of America's most popular word, writing with brevity and wit, and ranging across Ameri |