Should, Ought to, Need

Should Ought to

For giving advice or expressing a conclusion 'should' and 'ought to' are interchangeable. They are used to express the same ideas.

You should/ought to stop smoking.
He has been working on the project all week. He should/ought to be ready by this evening.

Should is also used in hypothetical situations:
Should anyone call, take a message.
Call me should you need any help.

Should is used with 'imagine', 'say' and 'think' to give a tentative opinion:
I should think it will take us an hour to drive to Rome.

Need

'Need' expresses necessity:
You need to exercise more often. You're putting on weight.
You don't need to wear a tie if you don't want to.

Needn't have/Didn't need to

'Needn't have' is used to talk about an action that was done but was unnecessary.
We needn't have rushed to the airport. The flight was delayed.
I needn't have brought an umbrella. It didn't rain.

‘Didn't need to' is used to talk about an action that wasn’t done because it was not necessary.
I didn't need to call Mike. I met him in the street.

Lesson by Tristan, teacher at EC Malta English school

Now complete the following with 'should/ought to', should or need:

• 1. He's been studying hard. He _ do well in the exam.
  
  should/ought to
  needs
  
  
• 2. You _ to complete the whole form for your application to be processed.
  
  need
  should
  ought
  
  
• 3. Do I _ to apply in writing?
  
  need
  ought
  should
  
  
• 4. I _ think that the new motorway will be ready next month.
  
  need
  ought to
  should
  
  
• 5. _ you have any questions just ask anyone here for help.
  
  Ought to
  Should
  Need
  
  
• 6. You _ come so early. We’re not ready to start yet.
  
  should/ought to
  didn’t need to
  needn’t have
  
  
• 7. We _ our ID cards to get into the club.
  
  didn’t need
  should
  needn’t have
  
  
• 8. I _ imagine he’ll be tired after such a long flight.
  
  should
  need