(auxiliary) Be obliged to; have an obligation to; indicates that the subject of the sentence has some obligation to execute the sentence predicate or that the speaker has some strong advice but has no authority to enforce it. (auxiliary) ought to; speaker's opinion, or advice that an action is correct, beneficial, or desirable. (auxiliary) Will be likely to (become or do something); indicates a degree of possibility or probability that the subject of the sentence is likely to execute the sentence predicate. (auxiliary, subjunctive) Used as a variant of the present subjunctive. (auxiliary) simple past tense of shall. (auxiliary, formal, literary) A variant of would when used with first person subjects. A statement of what ought to be the case as opposed to what is the case. To make a statement of what ought to be true, as opposed to reality.