But there is another form of good-bye that is very commonly used, although mostly with good friends. It is very casual. It comes from a long time past when it was fashionable to use the French word when bidding farewell to friends: adieu. In the course of time, and with people from all over the German-speaking world pronouncing and mispronouncing the word, it somehow got an s attached to it. Then it lost its first syllable. And in time it became simply Tschis (CHUESS).

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