ENGLISH GRAMMAR
SHOULD - OUGHT TO - NEED
Verbs to give advice or express necessity.
SHOULD_OUGHT-TO
Should and ought to are interchangeable for advice and conclusions :
Need expresses necessity.
Should and ought to are interchangeable for advice and conclusions :
- You should / you ought to write to your grandmother.
- He has revised all day; he should / he ought to be ready for his exam.
- In hypothetical situations :
- Should anyone call, please take a message.
- Should you need any help, just call me.
- If I were you, I should leave.
(In this last example, 'would' is often used today.)
- With 'imagine', 'say' and 'think'
to give tentative opinions :
- I should think the journey will take about two hours.
- I should imagine we'll get a reply next week.
Need expresses necessity.
- In summer we need to drink more often (= it is necessary for us to drink often.)
- You needn't / you don't need
to take notes. You'll get a summary.
(=it is not necessary to take notes.) - Need I / Do I need to do this? (=Is it necessary for me to do this?).
- Needn't have is used to refer to an
action which was performed but later turned out to be unnecessary.
- We needn't have rushed to the airport; the flight was delayed.
- He needn't have taken a sweater; the weather was warm.
- Didn't need to is used to refer to an
action in the past which was not
performed because there was no need
for it. It was not necessary.
- We didn't need to show our passports - ID cards were accepted.