A. As an independent transitive verb. To owe; be indebted or under obligation for.B. As an auxiliary.Am (is, are, was, etc.) obliged or compelled (to); will (or would) have (to); must; ought (to): used with an infinitive (without to) to express obligation, necessity, or duty in connection with some act yet to be carried out.Am (is, are, was, etc.) to (do something specified by the infinitive): forming verb-phrases having the value of future and conditional tenses, and usually (and properly enough) called such.In the second and third persons shall implies authority or control on the part of the speaker, and is used to expresspromise; as, you shall receive your wages;command: as, thou Shalt not steal;determination; as, you shall go.Certainty or inevitability as regards the future.Interrogatively, shall or will is used according as the one or the other would be used in reply, and accordingly ‘shall I go?’ ‘shall we ho?’ ‘shall he go?’ ‘shall they go?’ ask for direction, or refer the matter to the determination of the person asked—that is, ‘shall I go?’ anticipates the answer ‘you shall go.’After conditionals, such as if or whether, and after verbs expressing condition or supposition, shall expresses simple futurity in all persons, the idea of restraint or necessity involved originally in the word shall being excluded by the context—thus:In the older writers, as for instance in the authorised version of the Bible, shall was used of all three persons.Shall, like other auxiliaries, is often used with an ellipsis of the following infinitive.The past tense should, besides the uses in which it is merely the preterit of shall, as above, has acquired some peculiar uses of its own. In some of these uses should represents the past subjunctive, not the past indicative. It is not used to express simple past futurity, except in indirect speech: as, I said I should [wasto] go; I arranged that he should [was to] go, Should is often used to give a modest or diffident tone to a statement, or to soften a statement from motives of delicacy or politeness: thus, ‘I should not like to say how many there are’ is much the same as ‘I hardly like,’ or ‘I do not like,’ etc. Similarly, ‘it should seem’ is often nearly the same as ‘it seems.’Should was formerly sometimes used where we should now use might.The distinctions in the uses of shall and will and of should and would are often so subtle, and depend so much upon the context or upon subjective conditions, that they are frequently missed by inaccurate speakers and writers, and often even by writers of the highest rank. There is a tendency in colloquial English to the exclusive use of will and (except after a conditional word) would. See will..Synonyms Ought, Should. See ought.n. An African siluroid fish of the genus Synodontis; specifically, S. schal of the Nile, a kind of catfish with a small mouth, long movable teeth in the lower jaw, a nuchal buckler, and six barbels. Also schal.