II. Verb-Phrase denoting Willingness, etc.

239. Shall in the second and third persons is not the sign of the future tense in declarative sentences.

It is used in commanding, promising, threatening, and expressing resolution, the volition being that of the speaker.

In prophetic language, shall is common in the second and third persons, even when there is no idea of commanding or the like.

The sun shall be turned into darkness and the moon into blood.—Joel ii. 31.

240. In military orders and official communications, custom permits the more courteous will in the place of shall in the second and third persons.

For shall and will in subordinate clauses, see [pp. 130–132].