In formal British English, should is often used in that-clauses after certain nouns and adjectives. Examples of such nouns and adjectives are: important, necessary, vital, essential, eager, anxious, concerned and wish. As you may have noticed, most of them refer to the importance of an action.
- It is important that she should be told.
- I am anxious that nobody should be left out.
- It is necessary that she should talk to the manager.
- It is essential that she should finish her studies.
Certain verbs expressing similar ideas can also be followed by that-clauses with should.
- She insisted that I should pay for the drinks.
- The doctor recommended that I should stop smoking.
In American English, this use of should is unusual. Subjunctives may be used instead.
- It is important that she be told.
- It is necessary that she talk to the manager.
- It is essential that she finish her studies.
Should in if-clauses
Should can be used in if-clauses. This structure is used to suggest that something is unlikely.
- If you should see James, tell him that he owes me a drink.
Should after in case
After in case, we often use should + infinitive. This structure is used to add the meaning ‘by chance’.
- I always take an umbrella in case it should rain.