Shall is used with the first person pronouns I and we to show future action.
- We shall be there by this time tomorrow.
- We shall all gather on the beach this weekend.
- We shall be having a vegetarian meal with the uncle who has become a vegetarian.
Shall is used for the following expressions.
Shall is used for questions.
Shall is used for all persons for emphasis.
- I shall say again that you are talking rubbish.
- Never shall we forget his dying words about nobody are going to look after his pets.
- You shall be made to pay dearly for your negligence.
Shall is usually contracted to ‘ll which typically is added to a subject pronoun (I, we, you, they, he, she, it).
- I’ll phone you this evening.
The negative form shall not is contracted to shan’t.
- I’m afraid I shall not (shan’t) be able to attend the meeting.
Shall can be used with second-person and third-person pronouns to give a command or impose a prohibition.
- He shall write a letter of apology to the club members.
- You shall leave now as he’s waiting for you.
- None of you shall be permitted to use my nickname again.
Shall can be used with second-person and third-person pronouns to talk about rules and laws.
- It shall be a breach of club rules to drink alcohol in the clubhouse.
- Candidates shall comply strictly with the instructions.
- There shall be total silence during recording..
Should is the past form of shall, and like all the other modal verbs does not conjugate. Should functions as an auxiliary verb to express the following ideas.
- At the rate he’s drinking, he should get drunk before long. (Probability/possibility)
- He knows he should remain faithful if he wants his marriage to last. (Obligation/duty)
- If he should die now, what would become of his fleet of luxurious cars? (Condition)
- At the marketplace whom should I meet but my former sweetheart. (Surprise)
- You should go back to your husband. (Suggestion)
- What colour should we use for the kitchen walls? (Opinion)
- There should be a large crowd at the festival. (Expectation)
- You should have been there to see what really happened. (Wish)
- I should think it will take us more than two hours to complete it. (Emphasis)
Should is used in negative statements with the negative word not, which can be contracted.
- You should not (shouldn’t) have lied to her.
- You should not (shouldn’t) worry about the weather each time you go out.