As an auxiliary, shall indicates a duty or
   necessity whose obligation is derived from the person speaking; as, you
   shall go; he shall go; that is, I order or promise your going. It thus
   ordinarily expresses, in the second and third persons, a command, a
   threat, or a promise. If the auxillary be emphasized, the command is
   made more imperative, the promise or that more positive and sure. It is
   also employed in the language of prophecy; as, "the day shall come when
   . . . , " since a promise or threat and an authoritative prophecy
   nearly coincide in significance. In shall with the first person, the
   necessity of the action is sometimes implied as residing elsewhere than
   in the speaker; as, I shall suffer; we shall see; and there is always a
   less distinct and positive assertion of his volition than is indicated
   by will. "I shall go" implies nearly a simple futurity; more exactly, a
   foretelling or an expectation of my going, in which, naturally enough,
   a certain degree of plan or intention may be included; emphasize the
   shall, and the event is described as certain to occur, and the
   expression approximates in meaning to our emphatic "I will go." In a
   question, the relation of speaker and source of obligation is of course
   transferred to the person addressed; as, "Shall you go?" (answer, "I
   shall go"); "Shall he go?" i. e., "Do you require or promise his
   going?" (answer, "He shall go".) The same relation is transferred to
   either second or third person in such phrases as "You say, or think,
   you shall go;" "He says, or thinks, he shall go." After a conditional
   conjunction (as if, whether) shall is used in all persons to express
   futurity simply; as, if I, you, or he shall say they are right. Should
   is everywhere used in the same connection and the same senses as shall,
   as its imperfect. It also expresses duty or moral obligation; as, he
   should do it whether he will or not. In the early English, and hence in
   our English Bible, shall is the auxiliary mainly used, in all the
   persons, to express simple futurity. (Cf. Will, v. t.) Shall may be
   used elliptically; thus, with an adverb or other word expressive of
   motion go may be omitted.