What Are Auxiliary Verbs? (Including Examples and Usage)

We use auxiliary verbs—also known as helping verbs—all the time in American English. Even if you aren’t familiar with the definition of an auxiliary verb, there’s a good chance you’ve used several today.

Auxiliary verbs work with main verbs to form verb phrases, providing additional information about an action or state of being. They help communicate when something happens, whether it is ongoing or completed, and whether it is possible, necessary, or intended. They also help us form questions, negative statements, and the passive voice.

In this discussion, we’ll explain what auxiliary verbs are, identify their different types, and provide examples to reinforce how they contribute to our daily communication.

What Is an Auxiliary Verb?

An auxiliary verb is one that combines with a main verb to form a verb phrase. The auxiliary verb helps communicate information about an action’s tense, aspect, voice, or mood.

For example, compare I study with I will study. The auxiliary verb (will) in the second statement helps express a future action.

Consider also I work and I should work. The auxiliary verb in the second statement expresses advice or recommendation rather than simply stating an action.

Auxiliary verbs fall into two main categories: primary auxiliaries and modal auxiliaries.

The three primary auxiliary verbs are be, have, and do. They have different forms depending on the subject and, in some cases, tense (e.g., am, is, are; have, has, had; do, does, did).

Modal auxiliaries express meanings such as possibility, ability, permission, necessity, advice, and intention. The nine commonly recognized modal auxiliaries are can, could, may, might, must, shall, should, will, and would.

Unlike primary auxiliaries, modal auxiliaries do not change form to agree with their subjects (e.g., I will run, you will run, they will run).

Let’s look at more examples:

Sheila has already spent the money. (The primary auxiliary verb helps form the present perfect, connecting the past action to the present.)

I believe you will eat all of the donuts before lunch. (The modal auxiliary verb tells us the action is in the future tense.)

Lamar could ace the test if he studies for it. (The modal auxiliary verb informs us of possibility.)

How Are Auxiliary Verbs Used?

As we’ve discussed, auxiliary verbs provide additional information about the context and meaning of an action. They allow us to communicate more precisely than would be possible with main verbs alone.

One important function is helping us form negative statements. Imagine if we could say or write only I no go. That limitation would leave out important distinctions in meaning.

With the help of auxiliary verbs, we can express negative statements in varied ways, each conveying a slightly different meaning:

I will not go.	I would not go.
I shall not go.	I am not going.
I may not go.	I have not gone.
I cannot go.	I do not go.

As these examples demonstrate, auxiliary verbs help us communicate more than whether an action will or will not occur. They can also convey intention, possibility, ability, and the timing of an action.

Auxiliary verbs help us form questions as well: Will you go today? Has Sheila spent the money?

Continue Your Study of Grammar

Our website is full of grammar tips and guidance for helping you become an even more precise and eloquent communicator. Whether you have a subject in mind or would just like to browse, our archive has a wide range of articles for enhancing your mastery of American English. We also welcome you to share a comment or thought about the topic on this page in the comments section below.

Pop Quiz

Identify all of the auxiliary verbs in the sentences below.

1. Brian is surely going, but he does not know if Mariah will be joining him.

2. Do you know if it will rain tomorrow?

3. Carina should have an answer soon as long as Peter has properly finished his research.

4. The team is traveling by bus, and the fans can follow in their cars.

5. Najila would like to read more of those books if Petra can make them available.

 

Pop Quiz Answers

1. Brian is surely going, but he does not know if Mariah will be joining him.

2. Do you know if it will rain tomorrow?

3. Carina should have an answer soon as long as Peter has properly finished his research.

4. The team is traveling by bus, and the fans can follow in their cars.

5. Najila would like to read more of those books if Petra can make them available.

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