Should

We use 'should' for giving advice.

• 
  You should speak to him about it.
  
• 
  You should see a doctor.
  
• 
  You should ask a lawyer.
  

We use 'should' to give an opinion or a recommendation.

• 
  We should invest more in China.
  
• 
  They should do something about this terrible train service.
  
• 
  He should resign.
  

'Should' expresses a
personal opinion and is much weaker and more personal than 'must' or
'have to'. It is often introduced by ' I think'.

• 
  I think they should replace him.
  
• 
  I don't think they should keep the contract.
  
• 
  Do you think I should tell her?