Auxiliary Verbs: A Complete Guide + Examples

An auxiliary verb is a helping verb that appears before a main verb to form the predicate of a sentence. While auxiliary verbs perform a supporting role in a sentence, they also add context by expressing time, showing mood, or adding emphasis. 

Some auxiliary verbs are used to help form a question or reflect permission. Many times, auxiliary verbs are essential to a sentence.

Learn all about auxiliary verbs, then conveniently review grammar and spelling with the Originality.ai Grammar Checker.

Where Do Main Verbs Appear in a Sentence?

You can spot an auxiliary verb when the action in a sentence is not expressed by a single verb but by a verb phrase. That is the first clue to recognizing that a verb is not working alone: it has a helper. 

Examples:

• They have become great actors.
  
  • Main verb: become (to be)
  • Auxiliary verbs: have
• He is getting good grades because he has been studying a lot. 
  
  • Main verbs: getting, studying
  • Auxiliary verbs: is, has been (both forms of to be)
• I have given it a lot of thought. 
  
  • Main verb: given
  • Auxiliary verb: have

The last verb in the examples above is the main verb of the sentence. The verbs preceding the main verb are auxiliaries. 

It’s a Verb’s Usage That Is Auxiliary

Auxiliary verbs can, in some cases, act like a main verb. Each of the helping verbs above (to be, to have) can stand on its own in a sentence:

• They have a box of donuts.
• He is a good student.
• I have an idea.

It isn’t the verb itself that is auxiliary or main — the classification depends on how a verb is used. In these sentences, there is only one verb without any helping verbs. 

What Do Auxiliary Verbs Do, Exactly?

Examples of auxiliary verbs in action help clarify their function. The change an auxiliary verb makes may look small on the page but it makes a big impact.

Auxiliary verbs express tense and timing

Auxiliary verbs can reflect tense or time. In the examples below, the main verb is a form of “to go.”  The auxiliary verbs are bolded, and the verb tense is shown in (parentheses). 

Examples: 

• I go to work. (Present simple; no helping verb)
• I went to work. (Past simple, no helping verb)
• I will go to work. (Future simple)
• I have gone to work. (Present perfect)
• I had gone to work when I realized it was Sunday. (Past perfect)
• I will have gone to work by the time she wakes up. (Future perfect)
• I am going to work. (Present progressive)
• I was going to work when I saw the sunrise. (Past progressive)
• I will be going to work at 5 a.m. all next week. (Future progressive)
• I have been going to work at 5 a.m. all this week. (Present perfect progressive)
• I had been going to that job for five years when I started a new one. (Past perfect progressive)
• Today, I will have been going to the same job for five years. (Future perfect progressive)

In these examples, the auxiliary verbs change the tense, signaling to a reader when an action occurs. In this way, these small verbs make a significant impact. 

Be and Have Auxiliary Verbs

Eight different forms of be can be used as auxiliary verbs:

• am, are, is, was, were, be, being, been

Four forms of have can be used as an auxiliary:

• have, has, having, had

When used as an auxiliary, these be and have forms are combined with the main verb's present or past participle (the -ing form). 

Examples:

• I am running to the store.
• She is taking on a new project.
• We have been making a lot of changes this year.

Do as an Auxiliary Verb

Three forms of do can be used as auxiliary verbs, too:

• do, does, did

To add emphasis or form a question

When serving as auxiliary verbs, some forms of do add emphasis to a statement or help create a question.

Examples:

• We do hope you can come to the party.
  
  • Main verb: hope
• She does make the best carrot cake!
  
  • Main verb: make
• Does she want to come to the party?
  
  • Main verb: want
• Do they make their carrot cake from scratch?
  
  • Main verb: make
• We did see you there!
  
  • Main verb: see

To form a negative or emphatic statement

Used as an auxiliary verb, did, combined with not, helps to create a negative or emphatic statement. While less common, does can also act in this way. 

Examples:

• We did not see you at the party.
  
  • Main verb: see
• You did not say that!
  
  • Main verb: say

Modal Auxiliary Verbs

While the “be, have, and do” auxiliaries establish tense and form negatives and questions, the modal auxiliary verbs can have an additional influence on the main verbs they help. 

They express things like ability, possibility, permission, intention and expectations, to name a few. The most common modal auxiliary verbs are:

• can, could, will, would, shall, should, may, might, must

To help show ability

• You can make that cake using the right recipe.
• I can play soccer well.

To help make a request or ask permission

• Could you drive me to work, please?
• Will you lower that volume? 
• Shall I take your coat?
• Might you put that back where you found it?

To give permission

• Yes, you could borrow the library’s book.
• The boss said we can take tomorrow as a holiday.

To indicate expectations or offer advice

• You should lower that volume.
• When a tree is removed, you should plant a new one.

To predict or express a possibility 

• I might get an A on that paper.
• They could get a lot of rain tonight.

To express conditions

• If I get off work early, we can go to dinner.
• If you lend me a book, I will bring it back. 
• They said they would call when they arrived.

To show intention

• I will call you as soon as I get home.
• When the time comes, I will be there.

In addition to their many special uses, modal auxiliary verbs also express a change in tense, as illustrated in many of the examples above.

Auxiliary Verbs Are Essential to Writing

While most auxiliary verbs are short and serve in a helping capacity, they are crucial to good content creation. Without auxiliary verbs, writing would feel very one-dimensional. 

Try to write a story or piece of marketing copy with main verbs alone, and you’ll soon feel the absence of helping verbs, and the context they add to copy.

Review your content for proper use of auxiliary verbs, spelling, and grammar with the Originality.ai Grammar Checker.

Then, learn more grammar tips and best practices in our top guides:

• What Are Verbs? The Definitive Guide
• What Are Action Verbs? How to use Dynamic Verbs in Writing
• Stative Verbs: How to Use Them in Writing
• 6 Types of Adverbs