English Grammar in Use, Unit 51: Auxiliary Verbs
In each of these sentences there is an auxiliary verb and a main verb:
I have lost my keys.
She can’t come to the party.
The hotel was built ten years ago.
Where do you live?
In these examples have/can’t/was/do are auxiliary (=helping) verbs.
You can use an auxiliary verb when you don’t want to repeat something:
‘Have you locked the door?’ ‘Yes, I have.’ (=I have locked the door)
Gary wasn’t working, but Laura was. (= Laura was working)
Jessica could lend me the money, but she won’t. (=she won’t lend me the money)
Use do/does/did for the present and past simple:
‘Do you like onions?’ ‘Yes, I do.’ (=I like onions)
‘Does Simon live in London?’ ‘He did, but he doesn’t any more.’
You can use auxiliary verbs to deny what somebody says (= say it is not true):
‘You’re sitting in my place.’ ‘No, I’m not.’ (=I’m not sitting in your place)
‘You didn’t lock the door before you left.’ ‘Yes, I did.’ (=I locked the door)
We use have you? / isn’t she? / do they? etc. to show interest in what somebody has said, or to show surprise:
‘I’ve just seen Stephen.’ ‘Oh, have you? How is he?’
‘Lisa isn’t very well today.’ ‘Oh, isn’t she? What’s wrong with her?’
‘It rained every day during our holiday.’ ‘Did it? What a shame!’
‘James and Tanya are getting married.’ ‘Are they? Really?’
We use auxiliary verbs with so and neither:
‘I’m tired.’ ‘So am 1.’ (=I’m tired too)
‘I never read newspapers.’ ‘Neither do 1.’ (= I never read newspapers either)
Sarah hasn’t got a car and neither has Mark.
Note the word order after so and neither (verb before subject):
I passed the exam and so did Paul. (not so Paul did)
Instead of neither, you can use nor. You can also use not … either:
‘I don’t know.’ ‘Neither do I.’ or ‘Nor do I.’ or ‘I don’t either.’
I think so / I hope so etc.
After some verbs we use so when we don’t want to repeat something:
‘Are those people Korean?’ ‘I think so.’ (= I think they are Korean)
‘Will you be at home this evening?’ ‘I expect so. (= I expect I’ll beat home … )
‘Do you think Kate has been invited to the party?’ ‘I suppose so.’
In the same way we say: I hope so, I guess so and I’m afraid so.
The usual negative forms are:
I think so / I expect so ___,
I hope so / I’m afraid so / I guess so ___,
I suppose so ___,
I don’t think so / I don’t expect so
I hope not / I’m afraid not / I guess not
I don’t suppose so or I suppose not
‘Is that woman American?’
‘Do you think it will rain ?’
‘I think so. / I don’t think so.’
‘I hope so. / I hope not.’ (not I don’t hope so)