UK:*UK and possibly other pronunciationsUK and possibly other pronunciations strong: /ˈʃʊd/, weak: /ʃəd/US:USA pronunciation: IPA and respellingUSA pronuncation: IPA/ʃʊd/ ,USA pronunciation: respelling(shŏŏd)

From the verb shall: (⇒ conjugate)
should is: Click the infinitive to see all available inflections
v aux past
WordReference Collins English Usage © 2020
should - ought to
You use should or ought to to say that you expect something to happen.
We should be there by dinner time.
It ought to get easier with practice.
You use should or ought to with have and an -ed participle to say that you expect something to have happened already.
You should have heard by now that I'm O.K.
It's ten o'clock, so they ought to have reached the station.
You also use should or ought to with have and an -ed participle to say that something was expected to happen, but did not happen.
Bags which should have gone to Rome were sent to New York.
The project ought to have finished by now.
Be careful
You must use have and an -ed participle in sentences like these. Don't say, for example, ‘The project ought to finish by now’.
moral rightness
You use should or ought to to say that something is morally right.
Crimes should be punished.
I ought to call the police.
giving advice
You can say you should or you ought to when you are giving someone advice.
I think you should go see your doctor.
I think you ought to try a different approach.
negative forms
Should and ought to have the negative forms should not and ought not to.
This should not be allowed to continue.
They ought not to have said anything.
The not is not usually pronounced in full. When you write down what someone says, you write shouldn't or oughtn't to.
You shouldn't dress like that, Andrew.
They oughtn't to mention it.
When you make a negative statement with ought in American English, you can omit to:
You oughtn't answer the door without your shirt on.
WordReference Collins English Usage © 2020
shall - will
‘shall’ and ‘will’
Shall and will are used to make statements and ask questions about the future.
Shall and will are not usually pronounced in full after a pronoun. When writing down what someone has said, the contraction 'll is usually used after the pronoun, instead of writing shall or will in full.
He'll come back.
They’ll be late,' he said.
Shall and will have the negative forms shall not and will not. In speech, these are usually shortened to shan't /ʃɑːnt/ and won't /wəʊnt/. Shan't is rather old-fashioned, and is rarely used in American English.
I shan't ever do it again.
You won't need a coat.
It used to be considered correct to write shall after I or we, and will after any other pronoun or noun phrase. Now, most people write will after I and we, and this is not regarded as incorrect, although I shall and we shall are still sometimes used.
I hope some day I will meet you.
We will be able to help.
I shall be out of the office on Monday.
There are a few special cases in which you use shall, rather than ‘will’:
You can make a suggestion about what you and someone else should do by asking a question beginning with ‘Shall we...?
Shall we go out for dinner?
You can also suggest what you and someone else should do by using a sentence that begins with ‘Let’s...' and ends with ‘...shall we?
Let's have a cup of tea, shall we?
asking for advice
You can use shall I or shall we when you are asking for suggestions or advice.
What shall I give them for dinner?
Where shall we meet?
You can say ‘Shall I... ?’ when you are offering to do something.
Shall I shut the door?
Will also has some special uses:
You can use will you to make a request.
Will you take these upstairs for me, please?
Don't tell anyone, will you?
Requests, orders, and instructions
You can also use will you or the negative form won't you to make an invitation. Won't you is very formal and polite.
Will you stay to lunch?
Won't you sit down, Sir?
Will is sometimes used to say that someone or something is able to do something.
This will get rid of your headache.
The car won't start.
Be careful
You don't normally use ‘shall’ or ‘will’ in clauses beginning with words and expressions such as when, before, or as soon as. Instead you use the present simple. Don't say, for example, ‘I’ll call as soon as I shall get home'. Say ‘I’ll call as soon as I get home'.
'should' also found in these entries:

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