"Must necessitatem innuit. Debeo, oportet, necesse est urere, I must burn. Aliquando sed rarius in præterito dicitur must (quasi ex must'd seu must't contractum). Sic, si de præterito dicatur, he must (seu must't) be burnt, oportebat uri seu necesse habuit ut ureretur."—Wallis, 107.
9. Auxiliary derived from the idea of action—do.
C. Classification of auxiliary verbs in respect to their mode of construction.—Auxiliary verbs combine with others in three ways.
1. With participles.—a) With the present, or active, participle—I am speaking: b) With the past, or passive, participle—I am beaten, I have beaten.
2. With infinitives.—a) With the objective infinitive—I can speak: b) With the gerundial infinitive—I have to speak.
3. With both infinitives and participles.—I shall have done, I mean to have done.
D. Auxiliary verbs may be classified according to their effect.—Thus—have makes the combination in which it appears equivalent to a tense; be to a passive form; may to a sign of mood, &c.
This sketch of the different lights under which auxiliary verbs may be viewed, has been written for the sake of illustrating, rather than exhausting, the subject.
[§ 492]. The combination of the auxiliary, have, with the past participle requires notice. It is, here, advisable to make the following classifications.
1. The combination with the participle of a transitive