IDIOM AND SLANG

Idiom and slang are often hard to distinguish.

They oft so mix，the difference is too nice

Where ends the virtue，or begins the vice.

Theoretically, idiom is standard English and slang is not. But it is not always possible to assign a certain expression to its own territory. “It is slang，” some say. But others say，“It was slang，but is idiom.” And still others may say，“It may be considered both slang and idiom；for it has been slang for a long time but is getting the idiomatic franchise.” The fact seems to be that most slang expressions perish, but some survive and become what we call idiomatic expressions or idioms. In other words, slang is called slang，but when it gets established in standard English，none dare call it slang.

As you may have learnt from some composition book，slang should be avoided in writing. Quite true. But to Chinese students of English this is an unnecessary warning；for they are not liable to use slang at all. They often violate idiom，but they never use slang.

Some knowledge of slang，however，every Chinese student of English ought to possess. In fiction，drama，even newspapers，there is a good deal of slang，especially in dialogue.

A single word may be slang；for example，“peckish”，meaning hungry. A word that is not slang in itself may have its slang sense；for example，“blooming”，meaning dammed. Most slang expressions are phrases；for example， “all over the shop”，meaning everywhere.

As I have said，idiom and slang are often hard to distinguish. “All over the shop” is certainly slang，though it may cease to be slang in ten or twenty years. “At once” （meaning immediately） is certainly an idiom，though it may have been slang a long，long time ago. “Come down with” （meaning pay） seems to me to be neither a full idiom nor a full slang phrase.