An auxiliary is a short verb prefixed to one of the principal parts of an other verb, to express some particular mode and time of the being, action, or passion.  The auxiliaries are do, be, have, shall, will, may, can, and must, with their variations.

OBSERVATIONS.

OBS. 1.—­The present, or the verb in the present tense, is radically the same in all the moods, and is the part from which all the rest are formed.  The present infinitive is commonly considered the root, or simplest form, of the English verb.  We usually place the preposition TO before it; but never when with an auxiliary it forms a compound tense that is not infinitive:  there are also some other exceptions, which plainly show, that the word to is neither a part of the verb, as Cobbett, R. C. Smith, S. Kirkham, and Wells, say it is; nor a part of the infinitive mood, as Hart and many others will have it to be, but a distinct preposition. (See, in the Syntax of this work, Observations on Rule 18th.) The preterit and the perfect participle are regularly formed by adding d or ed, and the imperfect participle, by adding ing, to the present.

OBS. 2.—­The moods and tenses, in English, are formed partly by inflections, or changes made in the verb itself, and partly by the combination of the verb or its participle, with a few short verbs, called auxiliaries, or helping verbs.  This view of the subject, though disputed by some, is sustained by such a preponderance both of authority and of reason, that I shall not trouble the reader with any refutation of those who object to it.  Murray the schoolmaster observes, “In the English language, the times and modes of verbs are expressed in a perfect, easy, and beautiful manner, by the aid of a few little words called auxiliaries, or helping verbs.  The possibility of a thing is expressed by can or could; the liberty to do a thing, by may or might; the inclination of the will, by will or would; the necessity of a thing, by must or ought, shall or should.  The preposition to is never expressed after the helping verbs, except after ought.”—­Alex.  Murray’s Gram., p. 112.  See nearly the same words in Buchanan’s English Syntax, p. 36; and in the British Gram., p. 125.

OBS. 3.—­These authors are wrong in calling ought a helping verb, and so is Oliver B. Peirce, in calling “ought to,” and “ought to have” auxiliaries; for no auxiliary ever admits the preposition to after it or into it:  and Murray of Holdgate is no less in fault, for calling let an auxiliary; because no mere auxiliary ever governs the objective case.  The sentences, “He ought to help you,” and, “Let him help you,” severally involve two different moods:  they are equivalent to, “It is his duty to help you;”—­“Permit him to help you.”  Hence ought and let are not auxiliaries, but principal verbs.