George Campbell’s rules of style:

In his Philosophy of Rhetoric (1776), the Scottish rhetorician George Campbell defines acceptable language as that which is national, reputable, and current.  As he explains it, for an expression to be standard it must not be confined to dialectal or provincial use, or to the language of unworthy speakers and writers, and it must be neither old-fashioned nor innovative.  Many of Campbell’s successors have adopted these criteria, despite the problems they entail.  For example, national usage frequently turns out to be that of a prestige dialect which may be localized either geographically or socially; the repute of speakers and writers is often a matter of contention; and the very fact that some of us are always older or younger than others means a current form for some speakers must be either archaic or innovative for the rest.

the shall/will rule

The shall/will rule was stated succinctly in Bishop Robert Lowth’s extremely popular Short Introduction to English Grammar (1762):

Will, in the first person singular and plural, promises or threatens; in the second and third persons, only foretells: shall on the contrary, in the first person, simply foretells; in the second and third persons, promises, commands, or threatens. . . . When the sentence is interrogative, just the reverse for the most part takes place. [41-42]  

For Lowth – who at the acme of his career was Bishop of London -- the distinctions are innovative rather than inbred: he remarks in a footnote that they are not observed in the King James translation of the Bible (1611), and his aim is clearly to introduce a rule to cover a new linguistic development.

But by the 19^th century, commentators on language saw the shall/will distinction as essential. To the American journalist Richard Grant White (1870) the proper use of shall and will is found only among those Americans who qualify as “fairly educated people of English stock,” (264), while the Fowlers (The King’s English, 1906) drastically limit its range to “the idiomatic use [which] comes by nature to southern Englishmen [but which] is so complicated that those who are not to the manner born can hardly acquire it.”  Despite this expression of despair, the authors present twenty-one pages of detailed explanation for readers seeking to master the shibboleth.

Wilson Follett devoted twenty-four pages of his Modern American Usage (1966) to a tortuous discussion of a rule which “can be coped with by anyone minded to take the pains without which expression can be accurate only by chance.”

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Lindley Murray’s Rules (1795), from An English Grammar: Comprehending the Principles and Rules of the Language, illustrated by appropriate exercises and a Key to the Exercises.

Definition: English grammar is the art of speaking and writing the English language with propriety.

Parts of speech:

A Substantive or noun is the any of any thing that exists, or of which we have any notion.

A Verb is a word which signifies to BE, to DO, or to SUFFER.

Rule I: A VERB must agree with its nominative case, in number and person : as “I learn;”  “Thou art improved ;”  “The birds sing.”

Rule IV: A Noun of multitude, or signifying many, may have a verb or pronoun agreeing with it, either of the singular or plural number; yet not without regard to the import of the word, as conveying unity or plurality of idea: as, “The meeting was large;” :The parliament is dissolved;” “The nation is powerful;” “… “The council were divided in their sentiments.”

Rule V: Pronouns must always agree with their antecedents, and the nouns for which they stand, in gender and number : as, “This is the friend whom I love;”  “That is the vice which I hate;” “The king and the queen had put on their robes;”  “The moon appears, and she shines, but the light is not her own.” 

sec. 7: We hardly consider little children as persons, because that term gives us the idea of reason and reflection; and therefore the application of the personal relative who, in this case, seems to be harsh :  “A child who.”  It, though neuter, is generally applied, when we speak of an infant or child : as, “It is a lovely infant;”  “It is a healthy child.”

Rule XVI. Two negatives, in English, destroy one another, or are equivalent to an affirmative.

It will, doubtless, sometimes happen, that . . . a strict adherence to grammatical rules, would render the language stiff and formal : but when cases of this sort occur, it is better to give the expression a different turn, than to violate grammar for the sake of ease, or even of elegance.

Avoid low expressions : such as, “Topsy turvy … left to shift for themselves …”

Avoid: the injudicious use of technical terms; be careful not to use the same word too frequently; avoid equivocal or ambiguous words

Syle: requires attention to three qualities -- purity, propriety, precision.

Don’t use foreign words, obsolete words, ungrammatical words. “A multitude of Latin words, in particular, have, of late, been poured in upon our language. On some occasions, they give an appearance of elevation and dignity to style; but they often render it still and apparently forced.”

Sentence length: Sentences, in general, should neither be very long, nor very short: long ones require close attention to make us clearly perceive the connexion of the several parts; and short ones are apt to break the sense, and weaken the connxion of thought.

Murray recommends: Clearness (related words must be placed as close to one another as possible), unity (don’t change the scene or topic), strength (don’t repeat or put in extra words; don’t end with adverbs, prepositions, or other “inconsiderable” words), a judicious use of figures of speech (they should be clear and well-motivated).

that/which: Creating a Shibboleth

As part of their mission to impose order where chaos once ruled, usage critics may invent grammatical rules to regulate our behavior, providing language with a logical structure that it actually lacks.  For example, both that and which can serve in restrictive relative clauses: “The book which [that] you recommended was stolen from the library.”  However, only which occurs in nonrestrictive ones: “The book, which you returned just last week, is now missing.”  In the late nineteenth century, some usage critics sought to neaten things up by limiting that to restrictive clauses, and which to nonrestrictive ones.  Although this distinction is advocated by Ayres (1882) and is elaborately discussed by H. W. and F. G. Fowler (1906), its status as a tentative and arbitrary innovation is most clearly stated in Henry Fowler’s Modern English Usage (1926):

The relations between that, who, & which, have come to us from our forefathers as an odd jumble, & plainly show that the language has not been neatly constructed by a master builder. . . . If writers would agree to regard that as the defining relative pronoun, & which as the non-defining, there would be much gain both in lucidity & in ease. 

With the exception of Evans and Evans (1957), who observe that most speakers and writers remain oblivious to this distinction, those twentieth-century usage critics who treat the issue favor this rule, despite the fact that -- or perhaps, because -- general practice probably still reflects Fowler’s assessment of the situation as a jumble.