How did slang begin?

Slang is a variation of or addition to standard speech. If you stop to think of it, you'll realize how many forms of slang there are.For example, slang may be formed by compounding words ("lowdown") or by clipping words ("pro", "mike", "pix") or abbrevation ("O,K.", "snafu", "q.t"), or onomatopoeia ("boom", "whiz", "bang"), or borrowing from foreign languages ("pronto", "savvy"), or by analogy ("Prak your hat", "He got pickled").These various forms of slang arise from many reasons and under many different conditions. One of the most common ways is among people who belong to the same group. It might be the same trade, profession, hobby, age, or social position. For example, students have their "lab" and their "gym". Second-hand car dealers have their "creampuffs" (good cars) and their "dogs" (bad cars). A waitress will say, "Drop two on", when she orders poached egs on toast.But the same slang word in one group may mean something else to another group. In the underworld, "cat" doesn't mean the same thing it does in the jazz world. Some social conditions tend to produce slang more easily. If there is exitement, crowding, or people have been suddenly assembled for a particular purpose (as in time of war), then a large number of slang words are formed. "Blitz", "doodlebug", and "walkie-talkie" were salng expressions created in the last world war.Sometimes one clever person may launch a new slang expression and it is picked up by a lot of people. In many cases, new expressions that were once considered slang have been accepted into the dictionary in time. Among these are "bet", "shabby", "chap", "cab", and "kidnap". Some words have lasted as slang for hundereds of years, as, for example, the word "booze".
-: Thanks :-