should

 
Pronunciation: /ʃʊd/

modal verb (3rd sing. should)

  • 1used to indicate obligation, duty, or correctness, typically when criticizing someone’s actions: he should have been careful I think we should trust our people more you shouldn’t have gone
  • indicating a desirable or expected state: by now pupils should be able to read with a large degree of independence
  • used to give or ask advice or suggestions: you should go back to bed what should I wear?
  • (I should) used to give advice: I should hold out if I were you
  • 2used to indicate what is probable: £348 m should be enough to buy him out the bus should arrive in a few minutes
  • 3 formal expressing the conditional mood:
  • (in the first person) indicating the consequence of an imagined event: if I were to obey my first impulse, I should spend my days writing letters
  • referring to a possible event or situation: if you should change your mind, I’ll be at the hotel should anyone arrive late, admission is likely to be refused
  • 4used in a clause with ‘that’ after a main clause describing feelings: it is astonishing that we should find violence here
  • 5used in a clause with ‘that’ expressing purpose: in order that training should be effective it must be planned systematically
  • 6(in the first person) expressing a polite request or acceptance: I should like some more, if I may we should be grateful for your advice
  • 7(in the first person) expressing a conjecture or hope: he’ll have a sore head, I should imagine ‘It won’t happen again.’ ‘I should hope not.’
  • 8used to emphasize to a listener how striking an event is or was: you should have seen Marge’s face
  • (who/what should —— but) emphasizing how surprising an event was: I was in this shop when who should I see across the street but Tobias

Origin:

Old English sceolde: past of shall

As with shall and will, there is confusion about when to use should and would. The traditional rule is that should is used with first person pronouns (I and we), as in I said I should be late, and would is used with second and third persons (you, he, she, it, they), as in you didn’t say you would be late. In practice, would is normally used instead of should in reported speech and conditional clauses: I said I would be late; if we had known we would have invited her. In spoken and informal contexts the issue rarely arises, since the distinction is obscured by the use of the contracted forms I’d, we’d, etc. In modern English uses of should are dominated by the senses relating to obligation (for which would cannot be substituted), as in you should go out more often, and for related emphatic uses, as in you should have seen her face! For a discussion on the use of should of instead of should have, see have (usage).