Why do we need sentence correction?

" The care extends to tiny details. For instance, you must choose repeatedly whether to carry over words from one construction to its parallel. It’s either “the beautiful and the damned” or “the beautiful and damned.” Such choices will occur hundreds of times in a paper if written in lucid parallels. Fitzgerald, seeking elegant variation, could have written “the beautiful folks and those people who are damned,” in which case the choice would not have been posed, and you would probably never have heard of F. Scott Fitzgerald. Other tools to line up word and thing are singulars and plurals, masculines and feminines. Unlike the inflected Latin and Anglo- Saxon from which it descends, English does not have cases and gender to keep related words hitched. Make use of what paltry resources we have. The following sentence, for example, is ambiguous because “them” can refer to so many things: “Owners of the original and indestructible powers of the soil earned from them [powers or owners?] pure rents, and that tenant farmers were willing to pay them [the rents? the owners? the powers?] indicates that these powers of the soil were useful.” The singular and plurals here are not essential to the meaning, and so they can be exploited to make it clear: “An owner of the ‘original and indestructible powers of the soil’ earned from them [now unambiguous because it agrees with the only plural referent available: the powers] pure rents, and that the tenant farmers were willing to pay him [unambiguous: the owner] indicates that these powers of the soil were useful.” The use of “she” alongside “he” can in like fashion become an advantage for clarity of reference as much as a blow for sexual equality. "
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"The inflected languages have more freedom of order than English. Homo canem mordet means the same thing as canem mordet homo, with only a difference of emphasis, but “man bites dog” and “dog bites man” are news items of different sorts. Yet much can be done with the order of an English sentence. With the order of an English sentence much can be done. It’s mainly a matter of ear: proper words in proper places. Tinker with the sentence until it works. The problems come with modifiers, especially with adverbs, which are free floating in English. The phrase “which is again merely another notation for ...” should be “which again is merely another notation for ... ” Moving the “again” prevents it from piling up against the other modifier. Or: “the elasticities are both with respect to the price” should be “both elasticities are with respect to the price.”
You should cultivate the habit of mentally rearranging the order of words and phrases of every sentence you write. Rules, as usual, govern the rewriting.
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In revision the trick is to delete any comma before “the,” as I just did after “In revision”: the “the” signals a new phrase quite well enough without the clunk of a comma. "
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"Rearrangement serve grace as well as clarity."
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"Use Verbs, Active Ones:
You should make sentences that hit the target in the middle. Write therefore with nouns and, especially, verbs, not with adjectives and adverbs. Carry a rifle. In revision the adjectives and adverbs should be the first to go"