The three essentials of the English language are: Purity, Perspicuity and Precision.
By Purity is signified the use of good English. It precludes the use of all slang words, vulgar phrases, obsolete terms, foreign idioms, ambiguous expressions or any ungrammatical language whatsoever. Neither does it sanction the use of any newly coined word until such word is adopted by the best writers and speakers.
Perspicuity demands the clearest expression of thought conveyed in unequivocal language, so that there may be no misunderstanding whatever of the thought or idea the speaker or writer wishes to convey. All ambiguous words, words of double meaning and words that might possibly be construed in a sense different from that intended, are strictly forbidden. Perspicuity requires a style at once clear and comprehensive and entirely free from pomp and pedantry and affectation or any straining after effect.
Precision requires concise and exact expression, free from redundancy and tautology, a style terse and clear and simple enough to enable the hearer or reader to comprehend immediately the meaning of the speaker or writer. It forbids, on the one hand, all long and involved sentences, and, on the other, those that are too short and abrupt. Its object is to strike the golden mean in such a way as to rivet the attention of the hearer or reader on the words uttered or written.