Sometimes spelt 'okay', takes pride of place as the most widely used expression in the English language. For the British, it may come as a surprise if not a shock that the most widely used expression in the language is American in origin. There have been many etymological theories over its origin but only the two most likely and generally accepted theories are given here. Because they both occurred in America at around the same time, the two theories may have contributed jointly to the origin of OK, the first citation of which is given as 1840 according to the OED and 1839 according to Merriam-Webster. The first theory, supported by the OED, is that OK made its appearance in the election campaign of Martin van Buren (1782-1862), who ran for president in 1834. Van Buren came from the town of Old Kinderhook near Albany in New York State. Banners and posters used in his election campaign prominently featured the letters OK as an abbreviation for the candidate’s hometown. Very soon, van Buren became known as ‘the guy from OK’ or ‘the OK guy’ and he was duly elected the eighth president of the United States in 1835. He turned out to be one of the most popular and best loved US presidents of all time. The second theory, supported by Merriam-Webster, maintains that OK is the sole surviving expression of a slang fad that was popular in New York and Boston c.1838-39 in which abbreviations of jocular and deliberate misspellings were used. For example, KG was short for ‘know go’ and OK was short for ‘oll korrect’. In any event, by around 1840, OK had passed into the American language as a general term of approval. It was adopted into British Standard English about 40 years later, around 1880. See also A - OK and Okey dokey.