English Grammar and Exercises for ESL learners.
SHOULD - OUGHT-TO - NEED
SHOULD_OUGHT-TOShould 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.
Should is also used :
- In hypothetical situations :
- Should anyone call, please take a message.
- Should you need any help, just call me.
- If I were you, I should
(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.
NEEDNeed 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 / DIDN'T NEED TO
- 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
because there was no need for it. It was not necessary.
- We didn't need to show our passports - ID cards were accepted.