Auxiliary Verbs: Your Ultimate Guide to English Grammar

Introduction to Auxiliary Verbs

Auxiliary verbs, also called “helping verbs,” are very important in the construction of English sentences. Unlike main verbs, which express the principal action or state of being in a sentence, auxiliary verbs assist in expressing grammatical nuances such as verbs to express tense, mood, and voice. This harmonious relationship between main verbs and auxiliary verbs (or helper verbs) forms the backbone of English syntax, allowing speakers and writers to articulate ideas with precision and variety.

In this comprehensive guide, we aim to explore everything about auxiliary verbs, focussing on their definition, the different types, and why they’re so important in English grammar. This guide is made especially for students learning English. We want to help you understand how helping verbs work in sentences. This will make your English clearer and help you get better at using the language.

people talking using auxiliary verbs

The Basics of Auxiliary Verbs

What are Auxiliary Verbs?

At its core, an auxiliary verb is part of a verb phrase that modifies another verb, enriching the sentence with additional grammatical or functional meaning. These verbs often precede the main verb in a clause and are essential in constructing various verb tenses, voices, and moods. For instance, in the sentence “She has finished her work,” the auxiliary verb “has” works together with the main verb “finished” to indicate a completed action that has relevance to the present moment.

Conjugated Form of the Auxiliary Verb

Conjugated forms of auxiliary verbs are essential in English to show different times, voices, and moods in sentences. When we conjugate an auxiliary verb, we change the form of the verb to match the subject (a pronoun or noun) and the tense we are using, which is essential for sentences to express tense clearly. This helps make our sentences clear about when and how something happens.

For example, the helping verb “to be” turns into “am,” “is,” or “are” when we talk about now, based on the subject. In the same way, “have” becomes “has” with he, she, or it for actions happening now. These changes help us show clearly when and what is happening.

Conjugated Forms

VerbFirst Person SingularSecond Person SingularThird Person SingularPlural (All Persons)Past Tense Singular/Plural
Be (Present)am (I am)are (You are)is (He/She/It is)are (We/You/They are)was/were (I/He/She/It was; We/You/They were)
Have (Present)have (I have)have (You have)has (He/She/It has)have (We/You/They have)had (All Persons had)
Do (Present)do (I do)do (You do)does (He/She/It does)do (We/You/They do)did (All Persons did)
This table breaks down all the different conjugations of verbs be, have and do.

Examples of Auxiliary Verbs & Verb Phrases

  1. “Is” in Present Continuous Tense:
    • “She is running a marathon this weekend.”
      • “She (pronoun) is running (action verb) a marathon this weekend.” This sentence uses “is” as a linking verb in a verb phrase.
  2. “Have” in Present Perfect Tense:
    • “They have completed their homework.”
  3. “Will” for Future Intentions:
    • “I will visit my grandparents next month.”
  4. “Can” for Ability:
    • “He can speak three languages fluently.”
  5. “Would” for Polite Requests:
    • “Would you mind turning down the music?”

Using Auxiliary Verbs in the Passive Voice

Auxiliary verbs like “be” change sentences to focus more on the action or what receives the action. For example, “The chef cooks the meal” becomes “The meal is cooked by the chef” in the passive voice. Here, “is” helps turn the focus to “the meal.” Learning to use auxiliary verbs in the passive voice lets English learners express ideas differently and more precisely.

Main vs. Auxiliary Verbs

The distinction between main (lexical) verbs and auxiliary (helping) verbs is fundamental to understanding their roles in English grammar. Main verbs carry the core meaning of a sentence—used as an action verb, they tell us what action is taking place or describe a state of being. Auxiliary verbs, on the other hand, provide additional information about the main verb’s time, modality, or aspect without carrying semantic weight on their own.

Consider the difference in these examples:

Verb TypeDefinitionExample
Main VerbExpresses the main action or state of beingShe reads books.
Auxiliary VerbHelps to form tenses, moods, and voices of main verbsShe is reading a book.

Introduction to the Primary Auxiliary Verbs: Be, Have, Do

The Three Main Auxiliary Verbs

The English language features three primary auxiliary verbs: be, have, and do. Each plays a unique role in sentence construction:

  1. Be: Used to form continuous tenses and the passive voice. Example: “He is running.” (continuous tense) and “The song was written by her.” (passive voice) To learn more about the verb “be”.
  2. Have: Essential for creating perfect tenses, signalling actions that are completed at the time of speaking but have relevance to the present. Example: “They have arrived.” To learn more about the verb “have”.
  3. Do: Used as a helping verb in negative sentences, questions, and for emphasis. Example: “Do you understand?” (question) and “I do like it!” (emphasis). To learn more about the verb “do”.

Action Verbs vs. Auxiliary Verbs

By mastering the use of these auxiliary verbs, English language learners can significantly improve their ability to communicate complex ideas and emotions, enhancing both their spoken and written proficiency. 

  • Action Verbs:
    • Describe the main action taking place. Example: “She runs every morning.”
    • Stand alone without needing another verb for the sentence to make sense.
  • Auxiliary Verbs:
    • Help express grammatical aspects like tense or mood. Example: “She is running every morning.”
    • Cannot stand alone in the sentence’s main clause and always accompany a main or action verb.

Types of Auxiliary Verbs

In English, we have five main types of auxiliary verbs that help us form sentences in different ways. Let’s look at each type:

  1. Passive “be”: This form is used when the action is being done to the subject, not by the subject. For example, “The movie was written by him.”
    More examples:
    • The book was read by the entire class. (The action of reading the book was done by the class, not the book itself.)
    • A new supermarket is being built in our neighbourhood. (The supermarket is the receiver of the action; it’s coming into existence.)
    • The letter had been sent before the news broke. (The sending of the letter happened prior to another past event.)
  2. Progressive “be”: We use this to talk about actions that are happening right now or were happening at a certain time in the past or will be happening in the future. For instance, “He is running” or “She was singing.”
    More examples:
    • They are watching a movie right now. (The action of watching is currently happening.)
    • We were walking home when it started to rain. (The action of walking was in progress in the past when another action occurred.)
    • You will be staying at the Hilton during the conference. (A future action is planned to be in progress.)
  3. Perfective “have”: This type helps us talk about actions that were finished in the past but are important in the present. Like, “I have eaten,” means I ate sometime before now, but it’s relevant at this moment.
    More examples:
    • She has visited France three times. (The visits happened in the past but are relevant now.)
    • They had finished the project before the deadline. (The finishing of the project is a past action that was completed before another past moment.)
    • We will have left by the time you arrive. (The action of leaving will be completed in the future before another action.)
  4. Modal verbs: These include can, could, may, might, must, should, will, and would. They are special because they are used to express different feelings about the action, like if it’s possible, necessary, or if we have permission to do it. A simple example is, “She can swim,” which tells us about her ability to swim.
    Modal auxiliary verb examples:
    • Can: “He can lift heavy weights.” (Ability)
    • Could: “She could come to the party if she finishes her work early.” (Possibility)
    • May: “May I borrow your pen?” (Permission)
    • Might: “There might be a strike tomorrow.” (Possibility)
    • Must: “You must see the doctor immediately.” (Necessity)
    • Should: “You should try the new restaurant.” (Advice)
    • Will: “I will help you with your homework.” (Future intention)
    • Would: “Would you like some coffee?” (Offer)
  5. Dummy “do”: This one is a bit different. We use “do” to make questions or negative statements, or to add emphasis. Like in questions, “Do you like pizza?” or in negations, “I do not want to go.”
    More examples:
    • Do (in questions): “Do you know where my glasses are?” (Asking for information)
    • Do not (in negations): “I do not like spicy food.” (Expressing a dislike)
    • Do (for emphasis): “I do want to go to the party, but I’m too busy.” (Stressing the desire to go)

Modal auxiliary verbs are fascinating because they change the meaning of the main verb in a sentence to show mood, possibility, ability, permission, or necessity.

They are unique because they don’t change their form based on the subject of the sentence, showcasing their role in a verb phrase without requiring an adverb to modify the meaning

Unlike other verbs that might add an ‘s’ or change form for different tenses, modals stay the same.

This makes them straightforward to use, whether you’re talking about yourself, someone else, or something that happened in the past or might happen in the future.

When using modal auxiliary verbs, the main verb often takes either the infinitive form without “to,” known as the bare infinitive, to express actions or states. For instance, “She can swim” or “You must leave” illustrate how modal verbs modify the infinitive form of the main verb to show possibility, ability, or obligation.

Modal VerbUseExample
CanAbilityShe can solve complex math problems with ease.
PossibilityIt can get very hot in Arizona during summer.
CouldPast AbilityI could climb trees effortlessly when I was a child.
Polite RequestCould you please pass the salt?
PossibilityWe could go to the beach tomorrow if the weather is nice.
MayPermissionMay I use your phone to make a call?
PossibilityThere may be a strike next week.
MightLess CertaintyI might go to the party, but I’m not sure yet.
SuggestionYou might want to check the oil level in your car.
MustObligationYou must wear a helmet when riding a motorcycle.
Logical ConclusionShe must be at home because her car is in the driveway.
ShouldAdviceYou should see a doctor if the pain persists.
ExpectationThe train should arrive in ten minutes.
WillFuture IntentionI will travel to Japan next year.
PromiseI will always love you.
WouldHypothetical SituationsI would travel more if I had more money.
Polite RequestWould you mind closing the window?

Modal verbs add colour and texture to our language, allowing us to express a range of meanings and attitudes towards the actions and events we discuss. Whether it’s about potentiality, necessity, or courtesy, modal verbs help us articulate our thoughts with greater precision and subtlety.

Using Auxiliary Verbs to Express Tense

Auxiliary verbs play a crucial role in forming different verb tenses in English, helping to express when an action occurs and its relation to the present moment. Let’s explore how auxiliary verbs contribute to continuous, perfect, and future tenses, providing clarity and depth to our sentences.

Continuous Tenses

Continuous (or progressive) tenses express actions that are ongoing. Here’s how auxiliary verbs help form these tenses:

  • Present Continuous: am/is/are + verb-ing (e.g., “She is reading.”)
  • Past Continuous: was/were + verb-ing (e.g., “They were dancing.”)
  • Future Continuous: will be + verb-ing (e.g., “I will be traveling.”)

Perfect Tenses

Perfect tenses indicate actions that have been completed, either in the past or by a specific future time, and still affect the present or future.

  • Present Perfect: have/has + past participle (e.g., “We have finished.”)
  • Past Perfect: had + past participle (e.g., “She had left.”)
  • Future Perfect: will have + past participle (e.g., “They will have arrived.”)

Perfect Continuous Tenses

Perfect continuous tenses combine aspects of the perfect and continuous tenses, showing actions that started in the past and are still ongoing or will be ongoing until a certain point in the future.

  • Present Perfect Continuous: have/has been + verb-ing (e.g., “I have been studying.”)
  • Past Perfect Continuous: had been + verb-ing (e.g., “You had been working.”)
  • Future Perfect Continuous: will have been + verb-ing (e.g., “He will have been sleeping.”)
Present Simpledo/does + base verbI do want.
Past Simpledid + base verbWe did go.
Present Continuousam/is/are + verb-ingHe is coming.
Past Continuouswas/were + verb-ingThey were watching.
Present Perfecthave/has + past participleShe has seen it.
Past Perfecthad + past participleI had left.
Future Simplewill + base verbYou will understand.
Modal Verbsmodal + base verbWe can see.
Table of more tenses expressed using auxiliary verbs.

Auxiliary Verbs in Different Dialects of English

The use of auxiliary verbs can vary slightly between different English dialects, such as British, American, Canadian, and Australian English. These variations can add local flavour to English while maintaining mutual intelligibility among speakers of these dialects.

The Use of Auxiliary Verbs Across English Dialects

British English (BrE)

  • “Have got” for possession: In BrE, “have got” is commonly used to express possession (e.g., “I’ve got a car.”) which might simply be “I have a car” in other dialects.
  • Use of “shall”: BrE sometimes uses “shall” to express the future, especially in formal contexts (e.g., “We shall overcome.”).

American English (AmE)

  • “Do” for emphasis: AmE often uses “do” for emphasis (e.g., “I do want to go.”) more frequently than BrE.
  • Past simple vs. present perfect: AmE may use the past simple where BrE would use the present perfect (e.g., “I already ate” vs. “I have already eaten.”).

Canadian English (CanE)

  • Canadian English often blends elements of both AmE and BrE, making it quite versatile. For example, Canadians might use “have got” like BrE but also adopt the AmE past simple usage in situations where BrE would use the present perfect.

Australian English (AusE)

  • Informal contractions: AusE is known for its informal contractions of auxiliary verbs, such as “gonna” for “going to” and “wanna” for “want to.”
  • “Have” for possession: Similar to BrE, AusE frequently uses “have got” for possession.

While these examples highlight some differences, the core function of auxiliary verbs remains consistent across dialects, ensuring clear communication and understanding among English speakers worldwide.

Advanced Uses of Auxiliary Verbs Used to Express Formality, Politeness and Hesitancy

Auxiliary verbs, especially modal auxiliary verbs, add a layer of sophistication to our communication, allowing us to express politeness, hesitancy, and formality with finesse. The choice of an auxiliary verb and its form can subtly change the tone of a sentence, reflecting the speaker’s intention and relationship with the listener.

Expressing Politeness

  • Could and Would: These modals are softer and more polite forms of asking or suggesting. For example, “Could you pass the salt?” is gentler than “Can you pass the salt?” Similarly, “Would you mind opening the window?” feels more considerate than “Will you open the window?”

Indicating Hesitancy

  • Might and Could: When you’re not sure about something or want to express a tentative suggestion, “might” and “could” are your go-to auxiliaries. “I might come to the party” or “You could try calling him” imply uncertainty or offer a gentle suggestion without assuming too much.

Adding Formality

  • Shall: This auxiliary verb introduces a formal tone, often used in official documents or ceremonious contexts. “Shall we proceed?” conveys a formal proposal rather than the more casual “Should we go on?”

Common Mistakes and Tips

Mistakes with auxiliary verbs are common, especially among English language learners. Here are some frequent errors and tips on how to avoid them:

Confusing “Have” and “Has”

  • Error: Misusing “have” and “has” in the present perfect tense. For example, saying “She have gone” instead of “She has gone.”
  • Tip: Remember that “has” is used with third-person singular subjects (he, she, it), while “have” is used with I, you, we, and they. For example, “I have seen that movie,” but “He has seen that movie.”

Incorrect Use of Modal Verbs

  • Error: Mixing up modal verbs, such as using “can” for permission instead of “may.”
    “Can I leave early today?” when asking for permission is more politely phrased as “May I leave early today?”
  • Tip: Practice the specific uses of each modal verb. Remember, “can” is for ability, while “may” is for permission – “May I go to the bathroom?”.

Correct Use of Auxiliary Verbs

  • Constructing Questions and Negatives:
    • Use “do” to form questions (“Do you understand?”) and negatives (“I do not understand.”), ensuring clarity in inquiries and negations.
  • Modal Verbs for Precision:
    • Choose modal verbs carefully to express necessity (“must”), advice (“should”), or ability (“can”), enhancing the sentence’s intended meaning.
  • Tense Accuracy with “Be” and “Have”:
    • Distinguish between “be” for ongoing actions (“He is running.”) and “have” for completed actions (“He has run.”) to correctly indicate action timing.

Overusing “Will” for Future Intentions

  • Error: Relying too much on “will” to talk about the future, even when “going to” is more appropriate.
    “I will go to the doctor tomorrow” for a plan that’s already decided, instead use “I am going to go to the doctor tomorrow.”
  • Tip: Use “going to” for plans or intentions decided before the moment of speaking and “will” for decisions made at the moment of speaking.
    Example for a sudden decision: “Look at those clouds! I think it will rain. I will take an umbrella.”

Strategies for Avoidance

  • Practice makes perfect: Regularly practising sentences with auxiliary verbs in different tenses and moods can help solidify your understanding and usage.
  • Read and listen: Expose yourself to a variety of English materials—books, articles, songs, and movies—to see and hear auxiliary verbs in context.
  • Get feedback: Don’t hesitate to ask for feedback from teachers or native speakers. They can provide valuable insights into your auxiliary verb usage and help correct mistakes.

Expert Insights for English Grammar

Experts in linguistics and English language teaching emphasize the crucial role auxiliary verbs play in mastering English. They argue that a deep understanding of these verbs is essential not only for forming correct sentences but also for expressing a wide range of meanings and nuances.

Teacher Brian, “Auxiliary verbs are the backbone of English tense and aspect systems. Grasping their use is key to achieving fluency. For instance, the subtle difference between ‘will’ and ‘going to’ can indicate certainty versus intention, a distinction that non-native speakers often find challenging.”

ESL Teacher John, “Practice is paramount. I recommend students immerse themselves in English media. Paying close attention to the context in which auxiliary verbs are used can provide insights into their nuanced applications.”

Experts suggest focusing on:

  • Contextual Learning: Engage with English in real-world contexts to see how auxiliary verbs function in various situations.
  • Active Usage: Regularly practice constructing sentences using different tenses and aspects to become comfortable with auxiliary verb usage.
  • Seek Feedback: Work with teachers or native speakers who can provide corrective feedback on auxiliary verb use.

The evolution of English, like all languages, is ongoing, influenced by cultural shifts, technological advancements, and global communication. Experts speculate on several ways auxiliary verbs might adapt or change in response to these factors.

Technological Influence: As voice recognition and AI become more integrated into daily life, concise and clear communication becomes crucial. Auxiliary verbs may see simplified forms for efficiency in digital communication.

Global English: The global nature of English, used as a lingua franca, might lead to more standardized forms of auxiliary verbs to accommodate non-native speakers. Simplification for clarity and ease of learning could be a trend.

Cultural Shifts: New forms of media and digital communication (texting, social media) often push languages to evolve. Auxiliary verbs might gain new abbreviated forms or uses in informal communication.

While the future is speculative, one thing remains clear: auxiliary verbs will continue to be a vital part of English, adapting to meet the needs of its speakers in an ever-changing world.


In this guide, we’ve covered the essentials of auxiliary verbs, including types like modal verbs and their roles in showing time, mood, and action in English sentences. We’ve looked at common mistakes and how to avoid them, and peeked into the future of English language trends.

Practice using auxiliary verbs in your everyday English to enhance your skills. The more you use them, the better you’ll get!

Frequently Asked Questions (FAQs)

What is an auxiliary verb? An auxiliary verb helps the main verb show action time, mood, or voice. “Be,” “have,” and “do” are common examples.

What do modal auxiliary verbs do? Modal verbs like “can,” “may,” and “must” express possibility, permission, and necessity, adding meaning to the main verb.

When to use auxiliary verbs? Use them for questions, negative sentences, different tenses, and expressing feelings about the action. They make your English clearer and more detailed.

What is an auxiliary verb used for? Auxiliary verbs, also known as helping verbs, are used to change the tense, mood, or voice of the main verb in a sentence. They help form questions, negative statements, and different verb tenses like the future, perfect, and continuous aspects, adding depth and detail to express when and how actions happen. For example, “is” in “She is running” helps indicate the action is ongoing.

How to identify the main and auxiliary verbs in English grammar? Main verbs show the action or state and answer “What is happening?” Auxiliary verbs, like “is” in “She is singing,” support the main verb by adding tense, mood, or voice details. Look for the action (“singing”) to find the main verb and any helper verbs (“is”) to spot the auxiliary. In “Can she swim?”, “can” is the auxiliary showing ability, and “swim” is the main verb.