auxiliaries

uses

• To avoid repetition. Gary wasn’t working, but Laura was. (= Laura was working)

• To say that sb/sth is the same. ‘I´m tired.’ ‘So am I.’ (= I’m tired too)

  ‘I never read newspapers.’ ‘Neither do I.’ (= I never read newspapers either)

• To say that someone/something is different. ‘I didn't study for the exam.' ‘I did'

• To respond and react to what people say. ‘I’ve just seen Steven.’ ‘Oh, have you? How is he?’

• To show emphasis. ‘You aren't paying attention to the class’ ‘Yes, I’m.’

• To make questions tags. ‘Karen plays the piano, doesn’t she?’