Conjunctions connect words, sentences, or parts of sentences.
RULE XXIII.—PREPOSITIONS.
Prepositions show the relations of words, and of the things or thoughts expressed by them.
RULE XXIV.—INTERJECTIONS.
Interjections have no dependent construction; they are put absolute, either alone, or with other words.
GENERAL OR CRITICAL OBSERVATIONS ON SYNTAX.
OBS. 1.—An explanation of the relation, agreement, government, and arrangement, of words in sentences, constitutes that part of grammar which we call Syntax. But many grammarians, representing this branch of their subject as consisting of two parts only, "concord and government" say little or nothing of the relation and arrangement of words, except as these are involved in the others. The four things are essentially different in their nature, as may be seen by the definitions given above, yet not so distinct in practice that they can well be made the basis of any perfect division of the rules of syntax. I have therefore, on this occasion, preferred the order of the parts of speech; each of which will form a chapter in the Syntax of this work, as each forms a chapter in the Etymology.
OBS. 2.—Agreement and concord are one and the same thing. Relation and agreement, though different, may yet coincide, and be taken together. The latter is moreover naturally allied to the former. Seven of the ten parts of speech are, with a few exceptions, incapable of any agreement; of these the relation and use must be explained in parsing; and all requisite agreement between any of the rest, is confined to words that relate to each other. For one word may relate to an other and not agree with it; but there is never any necessary agreement between words that have not a relation one to the other, or a connexion according to the sense. Any similarity happening between unconnected words, is no syntactical concord, though it may rank the terms in the same class etymologically.
OBS. 3.—From these observations it may be seen, that the most important and most comprehensive principle of English syntax, is the simple Relation of words, according to the sense. To this head alone, ought to be referred all the rules of construction by which our articles, our nominatives, our adjectives, our participles, our adverbs, our conjunctions, our prepositions, and our interjections, are to be parsed. To the ordinary syntactical use of any of these, no rules of concord, government, or position, can at all apply. Yet so defective and erroneous are the schemes of syntax which are commonly found in our English grammars, that no rules of simple relation, none by which any of the above-named parts of speech can be consistently parsed, are in general to be found in them. If there are any exceptions to this censure, they are very few, and in treatises still marked with glaring defects in regard to the syntax of some of these parts of speech.
OBS. 4.—Grammarians, of course, do not utter falsehoods intentionally; but it is lamentable to see how often they pervert doctrine by untruths uttered ignorantly. It is the design of this pandect, to make every one who reads it, an intelligent judge of the perversions, as well as of the true doctrines, of English grammar. The following citations will show him the scope and parts which have commonly been assigned to our syntax: "The construction of sentences depends principally upon the concord or agreement, and the regimen or government, of words."—Lowth's Gram., p. 68; Churchill's, 120. "Words in sentences have a twofold relation to one another; namely, that of Concord or Agreement; and that of Government or Influence."—Dr. Adam's Latin and English Grammar, p. 151. "The third part of Grammar is SYNTAX, which treats of the agreement and construction of words in a sentence."—E. G. Greene's Grammatical Text-Book, p. 15. "Syntax principally consists of two parts, Concord and Government."—Murray's Gram., p. 142; Ingersoll's, 170; Alger's, 51; R. C. Smith's, 119; and many others. "Syntax consists of two parts, Concord and Government."—Kirkham's Gram., p. 175; Wright's, 124. "The Rules of Syntax may all be included under three heads, Concord, Government, and Position."—Bullions's E. Gram., p. 87. "Position means the place which a word occupies in a sentence."—Ib. "These rules may be mostly ranked under the two heads of agreement and government; the remainder may be termed miscellaneous."—Nutting's Gram., p. 92. "Syntax treats of the agreement, government and proper arrangement of words in a sentence."—Frost's El. of Gram., p. 43. This last-named author, in touching the text of my books, has often corrupted it, as he does here; but my definitions of the tenses he copied without marring them much. The borrowing occurred as early as 1828, and I add this notice now, lest any should suppose me the plagiarist.