My chief objection to a constant use of slang is not because it is outside the pale of classical English, but because it is so ineffective and feeble.
As a rule, slang words and phrases are, in the main, pointless and weak, for the simple reason that we use one word for every occasion when it happens to be the craze; and before long it comes to means nothing at all, even if it chanced to mean anything at the start—which it seldom does.
Our grandmothers objected to their own set using slang on the ground that it was "unladylike." The modern girl smiles at the term. "Who desires to be 'ladylike'?" inquires the advanced young person of to-day. Yet our grandmothers were right fundamentally; with their generation, the word "lady" implied a woman of education, intelligence, and refinement. The user of slang is the person who lacks these qualifications; she has neither the wit nor the knowledge to employ a better and more expressive selection of words.
Slang indicates Ignorance
Slang indicates, not advanced ideas, but ignorance—any parrot can repeat an expression, it takes a clever person always to use the right word.
Many people who constantly employ any word that happens to be current, do not really know what they are saying, neither do they attach any weight to their words; they merely repeat some inanity, because they have not the brains to say anything more intelligent, or they are too indolent to use what brains they have.
Notice how a set of big schoolgirls will, at one time, use the word "putrid," let us say, and apply it to everything, from a broken shoe-lace to examinations. And women will call everything "dinkie," or "ducky," or something equally enlightening and artistic, working the word all day long until it is ousted by another senseless expression.
What power of comparison has a girl, such as one I met recently, who, in the course of ten minutes described a hat as "awf'ly niffy," a man as "awf'ly sweet," a mountain as "awf'ly rippin'," and another girl as an "awful cat"?
What does it all amount to, this perversion of legitimate words or introduction of meaningless ones? Nothing—actually nothing. That is the pity of it. If these "ornaments of conversation" enabled one to grasp a point better, to see things more clearly, or to arrive at a conclusion more rapidly, I, for one, would gladly welcome them, as I welcome anything that will save time and labour. But, unfortunately, they only tend to dwarf the intelligence and to lessen the value of our speech.
I have enlarged on the undesirability of slang, because many amateurs think it will give brilliance, or smartness, or up-to-date-ness to their work. But it doesn't. It obscures rather than brightens; it tends to monotony instead of smartness. The beginner will be wise to avoid it, unless it is required legitimately in recording the conversation of a slangy person.