Auxiliary verbs, also called helping verbs, are used with a main verb to create compound verb forms. Auxiliary verbs may be followed by one, two, or even three other verbs. Auxiliary verbs are used in affirmative statements, negative statements, and questions. Here are the English auxiliary verbs:
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This lesson provides general information regarding auxiliary verbs. To learn about an individual auxiliary verb, click on one of the links above.
The verbs BE, DO and HAVE are special because they can be used as auxiliary verbs or as main verbs. Here are examples as main verbs.
| subject | verb | |
| I | am | a student. |
| She | does | her homework at night. |
| Tom | has | two dogs. |
Auxiliary verbs are always placed in front of the main verb. The verbs BE, DO, and HAVE are conjugated for tense and person when they are used as auxiliary verbs. When the auxiliary verb is BE, the main verb takes the form of a present participle or an infinitive.
| subject | aux. verb | main verb | |||
| I | am | studying | English. | present participle | |
| Tom and Sue | were | eating. | |||
| The party | is | to begin | at noon. | infinitive | |
| They | were | to call | me. | ||
When the auxiliary verb is DO, it is followed by a verb in its base form.
| subject | aux. verb | main verb | |
| Tom | does* | drink | coffee. |
| We | did | take | the train. |
*Normally, the verb DO is not used in an affirmative sentence. Sometimes, however, it is used to contradict. See the lesson on DO.
When the auxiliary verb is HAVE, it can be followed by a past participle or an infinitive.
| subject | aux. verb | main verb | ||
| He | has | seen | the movie. | past participle |
| We | had | left | early | |
| I | have | to leave | now. | infinitive |
| They | had | to buy | a new TV. | |
Modal verbs are never conjugated and they are always followed by a base form of the main verb.
| subject | auxiliary modals | main verb | |
| Ideas | can | change. | |
| You | must | wait | here. |
Some statements use more than one auxiliary verb. Note that the first auxiliary verb is conjugated for tense and person. The following auxiliary verbs take the form of a present participle or a past participle. The main verb takes the form of a present participle or a past participle. Here are examples of sentences constructed with two auxiliary verbs.
| subject | aux. verb | aux. verb | main verb | |
| I | am | beginning | to feel | tired. |
| The wind | has | been | blowing | all day. |
Here are example sentences constructed with three auxiliary verbs.
| subject | aux. verb | aux. verb | aux. verb | main verb | |
| We | have | been | waiting | to go | home. |
| Tom | had | been | trying | to call | for hours. |
Note that auxiliary verbs are always placed between the subject and the main verb.
In questions, the auxiliary verb is separated from the main verb by the subject.
| Yes / No questions | |||
| aux. verb | sub. | main verb | |
| Is | she | studying | English? |
| Does | Tom | drink | coffee? |
| Has | he | seen | this film? |
| Will | you | call | me later? |
| Wh– questions | |||
| aux. verb | sub. | main verb | |
| When | are | you | leaving? |
| Where | does | Tom | work? |
| What | has | he | done? |
| Who | can | you | call? |
Auxiliary verbs are used with the negative adverb not to form negative statements. Note that the adverb not is placed between the auxiliary verb and the main verb.
| subject | aux. verb | adv. | main verb |
| I | am | not | playing. |
| They | did | not | come. |
| The plants | have | not | grown. |
| The oven | will | not | work. |
To see a detailed lesson on a specific auxiliary verb, click on a link below.
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