Auxiliary verbs are sometimes called helping verbs because they are needed to form most of the verb constructions The term verb constructions is used here for tenses. Some grammarians say that there are only two tenses in English (past and non-past).
So to them the present perfect continuous, for example, is not a tense in its own right but a verb form constructed with the auxiliary have. in English.The most used auxiliary verbs are the verbs to be, to do and to have.
For example: the auxiliary to do is needed to ask questions in the present and past simple tenses. To be is needed for the present and past continuous, and all the passive forms. The auxiliary to have is used in the present perfect and past perfect constructions.
Some constructions, such as the present perfect continuous, need more than one auxiliary.
Here are some examples of the common auxiliary verbs in action:
- Do you like German food?
- Does your mother speak English?
- Did you come to school yesterday?
- Why are you talking? You should be listening to me!
- I was having a bath when you called!
- A new road is being built behind the school.
- Have you done your homework?
- My father has never visited the USA.
- How long have you been living in Germany?
- By this time next year I will have been learning English for 35 years!
Other common auxiliary verbs are: will, should, would, can, must, might, may, could. These verbs are usually called modal verbs.
The auxiliary verbs are very often contracted. For example, you can say I'm playing tennis tomorrow, instead of I am playing tennis tomorrow.
The contracted form (which needs an apostrophe) is more likely to be used in spoken language. So, for example, it would be a little unusual to ask your friend: Why did you not call me yesterday? More probable is: Why didn't you call me yesterday?
The short form itself often has two alternatives, which are equally usual and correct. For example:
- She's not going to the dance.
She isn't going to the dance.
- I haven't seen him for ages.
- I've not seen him for ages.
Firstly, the non-contracted auxiliary form is used in spoken language when the speaker wants to emphasize what she is saying. For example:
- Why don't you call him? - I have called him.
- I do not want to see him again.
Secondly, if you are doing a written report or essay, it is more usual to write the full auxiliary form: Why did America not join the war until 1941? (instead of Why didn't America...? ).
The auxiliaries to be and to have are used to form the progressive and perfect aspects. Here you can find more information about verb aspect.
Most of the interactive quizzes in the Verb grammar: Tenses drop-down menus on the Grammar index practise verb constructions that include auxiliary verbs.