Auxiliary Verb



  • If you really want to master grammar, master the auxiliaries. They are, in my opinion are of utmost importance in grammar……so let’s learn them in detail…..
  • Definition: The words which help the main verb in different ways are called as auxiliary verbs. As they help the main verb, they are also called as helping verbs.

A verb performs three functions:

1, to show action

  1. to show tense
  2. to handle the subject. (This is the most ignored part and needs attention)
  • The auxiliary verb helps the main verb in two ways
  1. to show tense
  2. to handle the subject.

Ex. I                   am                      teaching

Subject     helping verb            main verb

There are two types of model auxiliary verbs

  1. primary
  2. modal
  • Primary Auxiliary

The auxiliary verbs which help the main verb mainly in the formation of tenses & handling subject are called as primary auxiliary

There are three types of Primary auxiliary verbs.

  1. To be
  2. To do
  3. To have
  • Auxiliaris of to be

Present          past          other

am                was            be

is                 were           been

are                                   being


Use 1.these are used in the formation of continuous tense

  • In the continuous tense we use the – ing form of verb. The – ing form does not show any tense because -ing is added to the basic verb hence , to show the tense we should use any appropriate auxiliary of to be according to the tense & subject.
  • Structure of any continuous tense

subject +to be+ -ing

  • Present continuous tense

Subject +am /is /are + -ing

  • past continuous tense

subject +was /were+ -ing

eg.1] He is drinking water.                           2] They were reading.

Use 2. In the formation of passive voice:

In passive voice we always use the third form [past participle] which does not show any tense. So, auxiliary of to be helps to shows tense & handle the subject.

Structure of Passive voice.

subject+ to be + past participle

  1. 1. I sing songs. (Active)

Songs are sung by me. (Passive)                    

  1. They wrote a story. (Active)

            A story was written by them. (Passive)

*We cannot form continuous tense & passive voice without auxiliary of to be.

*After every auxiliary of to be we always use the Third (Past Participle) or fourth {-ing} form of verb.

(We will learn about the other auxiliaries of to be, like be, been, being in the course of time.)


Auxiliaries of To do:

These are the most important auxiliaries in my opinion. These auxiliaries most of the time are deciding factors of your grammar skill.

        Present         past

Do                  did


With I, we, you ,they, or any plural subject we use- do

With He, she, it or any third person singular subject we use –does

Here we must understand that there are total six types of subjects:

First person singular-I

First person plural –we

Second person singular – you

Second person plural – you

Third person plural – they

Third person singular – he, she it or any name.

Except third person singular all subjects take Do

Only third person singular takes does.

Now, focus on this third person singular, whenever you think about present tense. It always demands something different.

With all subjects in past tense, we use Did


Uses of auxiliaries of To Do

  1. In the formation of negative sentences

When the sentence has any helping verb, ‘not’ goes in the sentence with it.

We cannot use ‘not’ in the sentences without any auxiliary .It never goes in sentence alone.

  1. We can sing. = We cannot sing.
  1. She is dancing. = She is not dancing.
  1. You have passed. = You have not passed.

If the sentence does not have any auxiliary, then we have to use a suitable auxiliary of ‘to do’ to make it negative. We need to select an appropriate auxiliary of to do by keeping in mind, the tense, subject and its person.

  • They sing.

       They do no sing.

  • Jayant reads.

      Jayant does not read.

  • Teacher thought.

Teacher did not teach.

Exercise: Change the following sentences into negative and check your understanding.

1) They are running.           

2) She stands.

3) You speak.

4) I am reading.

5) People came.

6) Sanjay goes.

7) Ravana died.

8) Birds fly.

9) India should fight.

10) I adjust.

  1. INTERROGATIVE SENTENCES: Another important function of ‘to do’ is to help to change assertive sentence into interrogative.

When the sentence has any auxiliary [operator], we interexchange the place of subject & operator to make the sentence interrogative

  1. He can     play chess.

Subject    Operator

 Interrogative-Can he play chess?

(Operator : the nearest  auxiliary of the subject is called operator.)

  1. He is watching T.V.

Interrogative-Is he watching TV?

3.She has passed

Interrogative-Has she passed?

If the sentence does not have any auxiliary [operator] then we should use a suitable auxiliary of the to do according to tense and subject to make the sentence interrogative

  1. I speak Hindi.

 Interrogative- Do I speak Hindi?

  1. Anand sings.

       Interrogative-Does Anand sings?

  1. Dheeraj wrote.

       Interrogative- Did Dheeraj write?

After every auxiliary of to do we always use the basic form of verb.

The following exercise will definitely help you to understand the usage of auxiliary of to do in a better way. Go through it and check how auxiliaries of to do are used in them.


  1. We saw a tiger.
  2. We did not see a tiger.
  3. Did we see a tiger?
  4. When did we see a tiger?
  5. Where did we see a tiger?
  6. How did we see a tiger?
  7. Modi works hard.
  8. Modi does not work hard.
  9. Does Modi work hard?
  10. When does Modi work hard?
  11. Where does Modi work hard?
  12. How does Modi work hard?
  13. Birds flew in the sky.
  14. Birds did not fly in the sky
  15. Did birds fly in the sky?
  16. Where did birds fly?
  17. How did birds fly in the sky?
  18. When did birds fly in the sky?
  19. Teacher has given homework
  20. Teachers has not given homework
  21. Has teacher given homework?
  22. When has teacher given homework?
  23. How has teacher given homework?
  24. Where has teacher given homework?
  25. Boys drive cars.
  26. Boys do not drive cars
  27. Do boys drive cars?
  28. When do boys drive cars?
  29. Where do boys drive cars?
  30. How do boys drive cars?

Auxiliaries of TO HAVE


PRESENT               PAST

Have                         had


With I, We, you, they, or any plural subject– have

With He she, it, or any third person singular subject – has

(Have and has the same difference as it is between do as does)

With every subject in past tense we use had


 USES of auxiliaries of to have:

1.In the formation of perfect tenses. Without auxiliaries of to have you cannot form perfect tense.


s+ to have +past participle


S+ have/has + past participle

Eg:  1. Girls have given the test

  1. A girl has given the test


                         s + had +past participle

  1. 1. A girl/girls had given the test

After every auxiliary of to have we always use third form {past participle} of verb.

(One thing we must remember is that, all the primary auxiliaries can also work as main verbs.)