All verbs are either auxiliary verbs or main verbs. Auxiliary verbs, also called helping verbs, consist of primary verbs (be, have, do) and modal verbs (can, could, may, might, must, shall, will, etc). The most common auxiliary verbs are behavedo. Each of these has different forms; for example, the verb be/to be has eight different forms: amisarewaswerebebeing, and beenHave has these forms: havehashaving, and had, and do has these: dodoesdid, and done. Auxiliary verbs combine with other verbs (main verbs) to form tensesaspectvoicemodality and emphasis. They are usually placed in front of the main verbs, and there can be two or more auxiliary verbs in a sentence. They change the meaning or time of the action as expressed by the verbs: He does sing. / He is singing. / He has sung. Auxiliary verbs can be used as main verbs in a sentence.


All modal verbs are auxiliary verbs but not all auxiliary verbs are modal verbs. They include canwillmight and should: She can sing. / He will go. / They might come. / We should walk. The modal verbs are shown in the following table.

The auxilliary verbs are:

am is  are was were 
be being  been     
have has had     
do does did    
can could  will  would   
shall  should  may  might  must 



Auxiliary verbs combine with other verbs to form tenses 
Two verbs standing side by side in a sentence is a common sight. These two are most likely to be an auxiliary verb coming before the main verb.



  • Jill is riding an elephant. 
  • Jack has gone with Jill to the zoo. 


In the examples above, the first verb in each pair (ishas) is the auxiliary verbwhile riding and gone are the main verbs. The two verbs in each sentence combined to form a verb tense. 

In the first sentence, the auxiliary verb is used with a present participle to form the present continuous tense: is riding. It tells us that the action is still going on, that is Jill is still riding the elephant. 

In the second sentence, the auxiliary verb is used with a past participle to form the present perfect tense: has goneIt tells us the action has been completed. 


Auxiliary verbs as main verbs

Auxiliary verbs do not always combine with the main verbs to form tenses. The auxiliary verbs behave, and do can be used independently as main verbs. When used on their own, they are no longer auxiliary verbs.



  • I am sleepy. / She is pretty. / He was tall. / We are lost. / We were tired.  .
  • It has a long tail. / You have good looks. / They had dinner together. 
  • do it every day. / Does she know you? Yes, she does. / He did nothing wrong.



 Auxiliary verbs combine with other verbs to form aspect



Progressive aspect:

  • The girl is smiling at the elephant.

Perfective aspect:

  • The monkey has eaten three bananas.

Habitual aspect:

  • He used to smoke many cigarettes every day.
Auxiliary verbs used to form passive voice
The auxiliary verb be is often used with a past participle to create the passive form of verbs.



  • He was arrested by the police on drug charges.
  • The elephant was given a quick bath.
  • Her car was driven off by her ex-boyfriend. 



Other areas in which the auxiliary verbs are used

Besides being used to give emphasis, the auxiliary verbs dodoes, and did are often used together with the main verbs to form negative sentences and questions.



  • I do like her long hair. 
  • She does mind what you said. 
  • He did try to ride the elephant.

Negative statements:

  • I do not (don't) like those noisy monkeys. 
  • She does not (doesn't) want to listen to my stories.
  • He did not (didn't) keep his promise. 


  • You carry a gun, don't you?
  • Does he carry a gun? 
  • Did they fight after the argument?



Modals or modal verbs are also auxiliary verbs. They are also called modal auxiliary verbscancould, will, would, maymight, shallshouldmustought toused to.  Modal verbs are used to express ability, etc.



  • She can drive a tractor. (Ability)
  • He could swim across the river. (Ability)
  • If you don't leave now, we could be late. (Possibility)
  • I will call you this evening. (Willingness)
  • He may know how to repair it. (Possibility)
  • You might like a ride in the roller coaster. (Suggestion)
  • She would like to join us. (wish) 
  • We must get up early tomorrow. (Necessity)  
  • They should follow the instructions. (Obligation)

 (See Lesson 10 for more on modal verbs.)


Auxiliary verbs often come in contracted forms: have is shortened to ‘ve; is/has to ‘s; and had/would/should/could to ‘d.




  • I'm quite sure I've lost my way. (= I am / = I have
  • It's the biggest dog in the neighbourhood. (= It is) 
  • She's naturally curly hair. (= She has
  • They'd already gone home. (= They had
  • We'd like to go now. (= We would
  • You'd stop thinking every girl dislikes you. (= You should
  • He'd speak seven languages? (= He could)