To owe; to be under obligation for.

To be obliged; must.

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.