What are auxiliary verbs?
Besides acting as the main verb of a sentence, verbs are also helpful in a number of other ways, which are not so obvious. There are also auxiliary or ‘helping’ verbs that are used in a variety of ways. The main auxiliary verbs are be, have and do.
They are used with main verbs to make specific tenses:
- He is coming. present continuous
- She wasn’t driving. past continuous
- We haven’t seen an eclipse before. present perfect
- She had dropped her keys. past perfect
The verb be + a past participle is also used to make passive forms:
- The road is mended once a year.
- The engines are made in Germany.
- The votes are being counted in the hall.
- The whales had been driven onto the shore.
The auxiliary verbs are used to make questions:
- Do you want a drink?
- Don’t you like opera?
- Have you finished the work yet?
- Which train do you think you’ll catch?
Auxiliary verbs are used to make exclamations:
- Wasn’t she awful!
- Haven’t you grown!
- Didn’t they do well!
- Isn’t it freezing!
To make questions tags:
- We’re very happy, aren’t we?
- It’s cold, isn’t it?
- You don’t like fish, do you?
- You haven’t had a happy childhood, have you?
Note that the verb to be is the most common verb in English and it is the only one that can operate as both a main verb and an auxiliary verb. It doesn’t need any additional help to make questions or negatives.
- I am very happy.
- Am I very happy?
- I’m not very happy.
Compare this with the verbs do and have which need additional help to make questions and negatives.
- I have a very large nose. I don’t have a very large nose.
- I do my piano practice at 6 o’clock. I don’t do my piano practice.
What’s a modal auxiliary verb?
They are also ‘helping’ verbs because they are used to express a range of meanings, such as certainty, probability, possibility, suggestion, permission, instructions, requests, obligations, necessity, ability and so on. The main modal auxiliary verbs are:
- can, could, may, might
- shall, should, will, would
- must, ought, to
- also need to be able to, have (got) to
The main types of use of modal auxiliary verbs
certainty / probability (must, will, ought to, can’t, should)
- He must be feeling very unhappy at the moment.
- She ought to forget him, and move on.
possibility (may, might, could, can)
- She might arrive on the 5 o’clock train.
- They may come on Sunday, but I’m not sure.
suggestion (may, could, shall, might)
- Shall we start again?
- You may want to read over your essay again.
permission (may, can, could)
- Can I connect this wire now?
- You may begin the examination.
instructions and requests (would, will, can, could)
- Can you explain that in words of one syllable?
- Could you close the door, please?
obligations / necessity (must, have to, have got to)
- I must send my mother a card on her birthday.
- I’ve got to re-write this essay.
ability (can, could, be able to)
- I couldn’t stop laughing!
- He won’t be able to shift that stone.