H.L. Mencken (18801956). The American Language. 1921.
wounded very bad, I sure was stiff, drank out of a cup easy, he looked up quick. Many more are in Lardner: a chance to see me work regular, I am glad I was lucky enough to marry happy, I beat them easy, and so on. And others fall upon the ear every day: he done it proper, he done himself proud, she was dressed neat, she was awful ugly, the horse ran O.K., it near finished him, it sells quick, I like it fine, he et hoggish, she acted mean, he loved her something fierce, they keep company steady. The bob-tailed adverb, indeed, enters into a large number of the commonest coins of vulgar speech. Near-silk, I daresay, is properly nearly-silk. The grammarians protest that run slow should be run slowly. But near-silk and run slow remain, and so do to be in bad, it sure will help, to play it up strong and their brothers. What we have here is simply an incapacity to distinguish any ponderable difference between adverb and adjective, and beneath it, perhaps, is the incapacity, already noticed in dealing with it is me, to distinguish between the common verb of being and any other verb. If it is bad is correct, then why should it leaks bad be incorrect? It is just this disdain of purely grammatical reasons that is at the bottom of most of the phenomena visible in vulgar American, and the same impulse is observable in all other languages during periods of inflectional decay. During the highly inflected stage of a language the parts of speech are sharply distinct but when inflections fall off they tend to disappear. The adverb, being at best the step-child of grammaras the old Latin grammarians used to say, Omnis pars orationis migrat in adverbiumis one of the chief victims of this anarchy. John Horne Tooke, despairing of bringing it to any order, even in the most careful English, called it, in his Diversions of Purley, the common sink and repository of all heterogeneous and unknown corruptions.
Where an obvious logical or lexical distinction has grown up between an adverb and its primary adjective the unschooled American is very careful to give it its terminal -ly. For example, he seldom confuses hard and hardly, scarce and scarcely, real and really. These words convey different ideas. Hard means unyielding; hardly means barely. Scarce means present only in small numbers; scarcely is substantially synonymous with hardly. Real means genuine;