Shall / Should

Shall (verb)

Shall is another way of saying should.
1. An example of shall is someone saying they’re are expected to do something; “You shall go to school.”
2. An example of shall is someone saying they will go to the beach if it’s sunny outside; “I shall go to the beach if it’s sunny outside.”

Shall (auxiliary verb)

used in the first person to indicate simple future time: I shall probably go tomorrow
used in the second or third person, esp. in formal speech or writing, to express determination, compulsion, obligation, or necessity: you shall listen
used in the statement of laws or regulations: the fine shall not exceed $200
used in questions about what to do: shall I invite them?
used in formal conditional subordinate clauses: if any man shall hear, let him remember

Shall (aux.verb)

Used before a verb in the infinitive to show:

Something that will take place or exist in the future: We shall arrive tomorrow.
An order, promise, requirement, or obligation: You shall leave now. He shall answer for his misdeeds. The penalty shall not exceed two years in prison.
The will to do something or have something take place: I shall go out if I feel like it.
Something that is inevitable: That day shall come.

Archaic

To be able to.
To have to; must.

Shall (Verb)

(third-person singular simple present shall, present participle -, simple past should, past participle -)

(modal auxiliary verb, defective) Used before a verb to indicate the simple future tense, particularly in the first person singular or plural.

I shall sing in the choir tomorrow

Used similarly to indicate determination or obligation, particularly in the second and third persons singular and plural.

(determination): You shall go to the ball!

(obligation): Citizens shall provide proof of identity.

Used in questions to suggest a possible future action.

Shall we go out later?

Usage notes

Shall is about one fourth as common relative to will in North America as in the UK. Some in North America may consider it formal or even pompous.
In the past, will and shall have been used similarly as auxiliary verbs for the future tense. The simple future tense traditionally uses shall for the first person (“I” and “we”), and will for the second and third persons.

I shall go.

You will go.

An emphatic future tense, with a sense of must, reverses the two words, using will for the first person and shall for the second and third person.

I will go.

You shall go.

Usage can be reversed in questions and in dependent clauses “”especially with indirect discourse. For example: Shall you do it? is equivalent in meaning to Will you do it? as it anticipates your response I shall do it. Or: he says that he shall win or he expects that he shall win report his saying I shall win, not I will win.

Sentence Examples

Tomorrow you each shall ride one.
Certainly. Shall I get a room at the hotel?
Little girls; which one shall I seize for my very own?
Where shall it be?
Where shall I choose as her final resting place?

http://sentence.yourdictionary.com/shall

Should (verb)

Should signifies something you ought to do or something that is a good idea or that something that may happen.
1. An example of should is when someone tells you that you ought to go to bed.
2. An example of should is when you believe you must obey the law
3. An example of should is when someone says they will do something if they might happen to win the lottery.

Should (auxiliary verb)

shall: I had hoped I should see you
used to express obligation, duty, propriety, or desirability: you should ask first, the plants should be watered weekly
used to express expectation or probability: he should be here soon, I should know by tomorrow
used to express a future condition: if I should die tomorrow, if you should be late
used in polite or tentative expression of opinion: I should think they will be pleased.

Should (aux.verb)

Past tense of shall

Used to express obligation or duty: You should send her a note.
Used to express probability or expectation: They should arrive at noon.
Used to express conditionality or contingency: If she should fall, then so would I.
Used to moderate the directness or bluntness of a statement: I should think he would like to go.

Usage Note: Just as they ignore the traditional rules governing the use of shall and will, Americans largely ignore the traditional rules governing the use of should and would. The two verbs are not always interchangeable, however. To express duty or obligation, should is required and functions as the equivalent of ought to: I (or you or he) should go. But would (and not should) is used to express willingness or promise (I agreed that I would do it) and to express habitual action in the past (In those days we would walk along the canal at night). Would also has the advantage of being a polite substitute for will in requests: Would you lend me a dollar? Either should or would can be used in the first person to express the future from the point of view of the past, but one should bear in mind that should sounds more formal than would: He swore that I should (or less formally, would) pay for the remark. The same principle applies to the verb in sentences that express a hypothetical condition or event: If I had known that, I would (or more formally, should) have answered differently. In the second and third persons, however, only would is used: She assured us that she would (not should) return. If he had known that, he would (not should) have answered differently. • Choosing which verb to use in conditional clauses, such as those beginning with if, can be tricky. In certain clauses, should is used for all three persons: If I (or you or he) should decide to go, we will need a larger car. If it should begin to snow, we will stay here tonight. Would is not acceptable in these if clauses, but it does appear in other kinds of conditional clauses: He might surprise you if you would give him a chance. The best advice is to follow what sounds most natural. When in doubt, writers can try a verb form in the indicative (if it begins to snow) or the subjunctive (if you were to give him a chance).

Should (Verb)

(auxiliary) Used to form the future tense of the subjunctive mood, usually in the first person.

If I should be late, go without me.

Should it rain, I shall go indoors.

Should you need extra blankets, you will find them in the closet.

(auxiliary) Be obbliged to; have an obligation to; ought to; indicates that the subject of the sentence has some obligation to execute the sentence predicate.

You should brush your teeth every day.

What do I think? What should I think?

(auxiliary) Will likely (become or do something); indicates that the subject of the sentence is likely to execute the sentence predicate.

You should be warm enough with that coat.

(modern) A variant of would.

Usage notes

Should has, as its most common meaning in modern English, the sense ought as in I should go, but I don’t see how I can. However, the older sense as the subjunctive of the future indicative auxiliary, shall, is often used with I or we to indicate a more polite form than would: I should like to go, but I can’t. In much speech and writing, should has been replaced by would In contexts of this kind, but it remains in conditional subjunctives: should (never would) I go, I should wear my new dress.

(obligation): Contrast with stronger auxiliary verb must which indicates that the subject is required to execute the predicate.
(likely): Contrast with stronger auxiliary verb must, which indicates that the subject certainly will execute the predicate.
See the usage notes at shall.

Related terms

shoulde (archaic spelling of should)
shouldst (archaic second-person singular of should)
should’ve (contraction of future perfect subjunctive auxiliary phrase should have)

Noun

(plural shoulds)

A statement of what should be the case as opposed to what is the case.

Should (auxiliary verb)

Variant of shall

should

used in the first person to indicate simple future time: I shall probably go tomorrow
used in the second or third person, esp. in formal speech or writing, to express determination, compulsion, obligation, or necessity: you shall listen
used in the statement of laws or regulations: the fine shall not exceed $200
used in questions about what to do: shall I invite them?
used in formal conditional subordinate clauses: if any man shall hear, let him remember

Sentence Examples

Alex cautioned that it would seriously reduce their odds of success, but they and the surrogate mother were agreeable to twins, if it should happen.
Such a pleasant day and evening should have ended with a restful night and happy dreams, but it didn’t.
It should have been an exciting moment, but frightening would have better described the sudden pounding of her heart.
Of course he would, and she should have.
They should be doing an ultrasound in a couple of weeks.

http://sentence.yourdictionary.com/should