Etaoin Shrdlu is a somewhat infamous phrase among language enthusiasts. It is pronounced “eh-tay-oh-in shird-loo” and is believed to be the twelve most common letters in English, in order of most frequently used to least frequently used. The expression came about from linotype typesetting machines. Were one to run a finger down the first and then second left-hand vertical banks of six keys on a linotype machine, it would produce the words etaoin shrdlu. Linotype machines were sometimes tested in this manner. Once in a while, a careless linotype machine operator would fail to throw his test lines away, and that phrase would mysteriously show up in published material. The full sequence is etaoin shrdlu cmfgyp wbvkxj qz.