269. Shall and will are not to be taken as separate verbs, but with the infinitive as one tense of a verb; as, "He will choose," "I shall have chosen," etc.
Also do may be considered an auxiliary in the interrogative, negative, and emphatic forms of the present and past, also in the imperative; as,—
What! doth she, too, as the credulous imagine, learn [doth learn is one verb, present tense] the love of the great stars? —Bulwer.
Do not entertain so weak an imagination—Burke.
She did not weep—she did not break forth into reproaches.—Irving.
270. The infinitive is sometimes active in form while it is passive in meaning, as in the expression, "a house to let." Examples are,—
She was a kind, liberal woman; rich rather more than needed where there were no opera boxes to rent.—De Quincey.
Tho' it seems my spurs are yet to win.—Tennyson.
But there was nothing to do.—Howells.
They shall have venison to eat, and corn to hoe.—Cooper.