What is an Auxiliary Verb?
An auxiliary verb (also called a helping verb) is a verb that adds functional or grammatical meaning to the main verb.
It helps express tense, voice, mood, or aspect.
Example:
“She is running.”
Here, is is the auxiliary verb helping the main verb running.
Terms You Should Know
Auxiliary Verb:
A verb that helps another verb form a tense, mood, or voice.
Main Verb:
The action word that carries the main meaning in a sentence.
Modal Auxiliary Verb:
A type of auxiliary verb that shows possibility, ability, permission, or obligation.
Semi-Auxiliary Verb:
Two or more words that function like a modal, e.g., have to, be going to.
Types of Auxiliary Verbs (With Examples)
| Type | Examples | Usage |
|---|---|---|
| Primary Auxiliaries | be, do, have | Form tenses, voice, questions |
| Modal Auxiliaries | can, should, must, will | Show possibility, obligation, advice |
| Semi-Auxiliaries | have to, be going to | Express necessity, future plans |
The Big Three Primary Auxiliary Verbs
1. Be
Forms continuous tenses and the passive voice.
Forms: am, is, are, was, were, been, being.
Example:
They are cooking dinner. (Present continuous)
2. Have
Forms perfect tenses.
Forms: have, has, had.
Example:
She has finished her project.
3. Do
Helps in questions, negatives, and emphasis.
Example:
I do like chocolate! (emphasis)
Modal Auxiliary Verbs: The Mood Changers
Modal verbs give extra meaning to the main verb. They are never conjugated — they stay the same!
| Modal Verb | Use | Example |
|---|---|---|
| can | Ability or permission | I can swim. |
| could | Past ability, polite requests | Could you help me? |
| may | Permission or possibility | You may leave now. |
| might | Small possibility | It might rain. |
| must | Strong obligation | You must wear a seatbelt. |
| shall | Future action (formal) | I shall return. |
| should | Advice | You should see a doctor. |
| will | Future certainty | She will succeed. |
| would | Hypothetical situations | I would travel if I could. |
Semi-Auxiliary Verbs: A Hidden Secret!
Semi-auxiliaries are combinations like:
have to (necessity)
be going to (future intention)
ought to (moral obligation)
Example:
I have to finish my homework tonight.
When Do We Use Auxiliary Verbs?
Auxiliary verbs help us:
Form different tenses (past, present, future)
Create questions and negatives
Form the passive voice
Add emphasis and politeness
Quick Tip:
If a sentence has more than one verb, there’s a good chance an auxiliary is involved!
Forming Tenses with Auxiliary Verbs
Here’s a super simple table you’ll want to screenshot:
| Tense | Structure | Example |
|---|---|---|
| Present Continuous | am/is/are + verb-ing | I am reading. |
| Past Continuous | was/were + verb-ing | She was cooking. |
| Future Continuous | will be + verb-ing | They will be arriving. |
| Present Perfect | have/has + past participle | We have finished. |
| Past Perfect | had + past participle | I had left early. |
| Future Perfect | will have + past participle | She will have graduated. |
| Present Perfect Continuous | have/has been + verb-ing | He has been studying. |
| Past Perfect Continuous | had been + verb-ing | They had been sleeping. |
| Future Perfect Continuous | will have been + verb-ing | She will have been working. |
Other Critical Uses of Auxiliary Verbs
Negatives:
She does not like pizza.
Questions:
Do you want tea?
Passive Voice:
The cake was baked by Tom.
Emphasis:
I do believe in magic!
Tag Questions:
You love dogs, don’t you?
Common Mistakes (And How You Can Avoid Them)
Forgetting “do” in negative sentences:
(“I not like it” ➔ I do not like it)Confusing modal verbs:
(“I must can swim” ➔ I must be able to swim)Overusing “be” forms unnecessarily:
(“He is goes to school” ➔ He goes to school)
How Auxiliary Verbs Work in Different Tenses
Auxiliary verbs are the quiet engine behind English verb tenses. They carry the main verbs into different times and situations — past, present, future, continuous, perfect — you name it!
Let’s break this down clearly:
1. Future Tenses (Modal: “Will”)
To talk about things that haven’t happened yet, we use the modal auxiliary verb will.
No fancy rules here — just will + base form of the main verb.
Examples:
She will travel to Japan next summer.
They will start the project next week.
Quick Insight:
In negative future sentences, simply add not after “will” → will not or the contraction won’t.
(I won’t forget your birthday!)
2. Continuous (Progressive) Tenses (Be + -ing)
When an action is ongoing, we use the auxiliary verb be plus the -ing form of the main verb.
Formula:
Be (am/is/are/was/were) + Main Verb + ing
| Tense | Example |
|---|---|
| Present Continuous | I am reading a book. |
| Past Continuous | She was painting all evening. |
| Future Continuous | We will be working late tonight. |
3. Perfect Tenses (Have + Past Participle)
Perfect tenses show completed actions that connect to another time — the present, the past, or the future.
Formula:
Have (have/has/had) + Past Participle of Main Verb
| Tense | Example |
|---|---|
| Present Perfect | They have arrived already. |
| Past Perfect | He had finished before noon. |
| Future Perfect | I will have completed the course by December. |
Pro Tip:
The past participle often looks different from the simple past.
Eat → Eaten
Go → Gone
Write → Written
4. Perfect Continuous Tenses (Have + Been + -ing)
Sometimes we need to show that an action started earlier and is still happening — that’s when the perfect continuous tense steps in.
Formula:
Have/Has/Had + Been + Main Verb + ing
| Tense | Example |
|---|---|
| Present Perfect Continuous | She has been studying for hours. |
| Past Perfect Continuous | We had been walking all afternoon. |
| Future Perfect Continuous | By next year, they will have been living here for a decade. |
Metaphor Check:
Think of auxiliary verbs like bridges. They link your message across time — whether it’s something you did, are doing, or will do!
Common Mistakes to Watch Out For
Here are a few traps even native speakers sometimes fall into:
Omitting the auxiliary:
(Wrong: I going to the store.)
(Right: I am going to the store.)Mismatching the tense:
(Wrong: He have finished the work.)
(Right: He has finished the work.)Using the wrong form of the main verb:
(Wrong: She has ate lunch.)
(Right: She has eaten lunch.)
FAQs On Auxiliary Verb in English
1. What is an auxiliary verb in English?
An auxiliary verb, also known as a helping verb, supports the main verb in a sentence. It helps form different tenses, moods, voices, and even questions. Examples include be, have, do, and modal verbs like can, will, and must.
2. How do auxiliary verbs differ from main verbs?
While main verbs show the primary action or state, auxiliary verbs assist by giving additional meaning. For example, in “She is running,” “running” is the main action, and “is” (auxiliary) shows the present continuous tense.
3. When should I use an auxiliary verb in English grammar?
You use auxiliary verbs to:
Create complex tenses (like have finished or is going)
Form questions (Did you eat?)
Make negatives (He does not like coffee)
Express modality (possibility, ability, obligation, etc.)
Construct the passive voice (The book was written by her.)
4. What are some examples of sentences with auxiliary verbs?
Here are a few examples:
I have seen that movie.
She is studying for her exams.
They can speak three languages.
We will travel next month.
The cake was eaten quickly.
Each example shows the auxiliary verb working together with the main verb.
5. Can a verb be both an auxiliary verb and a main verb?
Yes! Many auxiliary verbs can also act as main verbs depending on how they’re used.
For instance:
Auxiliary use: I have completed the project.
Main verb use: I have a car.