Grammar
Auxiliary verbs: use be, do, and have
Do you mix up be, do, and have? Look at the main verb to choose the right helper.
Be, do, and have help build questions, negatives, and tense forms. Match the helper to the main verb, then practice questions and short answers.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
Did you do it? did-yoo-DOO-it
The short answer
Be forms continuous and passive verbs; have forms perfect verbs. Use do with a base verb in simple-tense questions and negatives when no other helper is present, except with main-verb be.
She's working late tonight because she's started a new project.
Why it works: The first she's means she is; the second means she has. Tonight's work may be happening now or planned for later.
4 more examples
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Checking on a work phone call
Didn't you call the office this morning?
Use did with the plain verb call.
Not this:
Didn't you calledthe office this morning? What changes: Adding -ed after did doubles the past tense. -
Looking out the window
They're waiting outside for the bus.
The helper are joins with the -ing verb waiting.
Not this:They
're waitoutside for the bus. What changes: The helper be cannot pair with a base verb for an ongoing action. -
Talking about home
We've lived in this city for five years.
Use have with a past participle to connect the past to now.
Not this:We
're livedin this city for five years. What changes: Live has no direct object in this sentence, so it cannot form a passive here. Use have lived for a period continuing until now. -
Asking about a daily habit
Don't you drink green tea in the morning?
Use do to ask about daily routines.
Not this:
Aren't you drinkgreen tea in the morning? What changes: The helper aren't cannot pair with a base verb for a routine.
Quick check
Which sentence pairs the helping verb with the correct main verb form?
Talking about London
Answer: She's living in London right now.
Show the answer
Answer: She's living in London right now.
The helping verb be joins with an -ing verb for ongoing actions.
Read the full guide
At a coffee counter, you want to ask whether oat milk is available. Have is the main verb for possession here; a common question form uses do. In other sentences, have is itself a helper. The words that follow it show which job it is doing.
Match each helping verb correctly
The problem: Identify the helping verb in a question, negative, continuous, or perfect form.
Match the helper to the verb form and meaning. Be works with -ing for continuous forms and a past participle for passives. Have also takes a past participle, but makes a perfect form. Perfect forms can describe completed events or situations continuing up to a later time.
| Helper | Main verb form | Quick example |
|---|---|---|
| be (am, is, are, was, were): continuous | verb + -ing | They're waiting outside. |
| be: passive | past participle | The windows were cleaned yesterday. |
| do (do, does, did) | plain base verb | We didn't watch the film. |
| have (have, has, had) | past participle | I've finished my lunch. |
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She's writing a report right now.
Why it works: Use be with writing because the action is happening now.
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They've finished their breakfast.
Why it works: Use have with finished to show a completed task.
Your turn
We arranged a booking. Which sentence uses the present perfect to tell someone about it?
Checking on dinner plans
Answer: We've booked a table for seven tonight.
Show the answer
Answer: We've booked a table for seven tonight.
The helper have pairs with the past participle booked.
Keep main verbs plain after do
The problem: I changed the main verb to the past tense after did, and someone corrected me.
You ask your coworker about yesterday's meeting. The word did already carries the past time. You do not need to add -ed to the main action that follows.
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Not this:
Didn't you saw the news yesterday?Say: Didn't you see the news yesterday?
Didn't already shows the past, so keep see in its plain form.
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Not this:
She doesn't likes spicy food.Say: She doesn't like spicy food.
Doesn't carries the third-person -s ending, so like stays plain.
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Didn't they visit their grandparents on Sunday?
Why it works: Visit stays plain because didn't carries the past.
Your turn
Which question uses the correct form after did?
Asking about yesterday's flight
Answer: Didn't your sister arrive on time yesterday?
Show the answer
Answer: Didn't your sister arrive on time yesterday?
Did already shows past time, so the main verb stays plain.
Choose between be and do
The problem: I say 'Are you work here?' instead of 'Do you work here?' because I mix up be and do.
Use do with most main verbs in simple-tense questions. Continuous questions already have be; do is not added. Main-verb be makes its own questions. Negative questions often check an expectation or express surprise.
Ask about daily life with do and a base verb.
Don't you drive to work every day?
Use be + -ing to ask about an action in progress.
Aren't you driving right now?
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Are you tired after the journey?
Why it works: Are is the main verb here. It makes the question without do.
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Doesn't he live near the city center?
Why it works: This simple-tense question uses doesn't with the base form live.
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Isn't he staying at a hotel this week?
Why it works: Staying at a hotel is temporary, so use isn't with staying.
Your turn
You think your neighbor has a regular job at the hospital. Which question uses the present simple to check this?
Talking to a new neighbor
Answer: Don't you work at the hospital downtown?
Show the answer
Answer: Don't you work at the hospital downtown?
Use do with a base verb to ask about regular habits.
Keep helping verbs in questions
The problem: I forget to put helping verbs in questions, so I just say 'Where you go?'.
In most questions, put the first auxiliary before the subject. Add do in simple-tense questions when no helper is present, except with main-verb be. When who or what is the subject of an affirmative question, do is normally unnecessary. A modal such as can also comes before the subject without do.
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Who left this bag beside the door?
Why it works: Who is the subject, so this affirmative question does not need did.
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Why aren't you going to the station?
Why it works: Put aren't before the subject you.
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Haven't you seen my coat anywhere?
Why it works: Haven't comes before you in this negative present-perfect question.
Your turn
Type the missing helping word to complete the question.
Asking about holiday plans
Answer: You've packed your bags, but where are you going tonight?
Show the answer
Answer: are
Questions with an -ing verb need the helper are before you.
Before you go
Question 1 of 3
Which question correctly asks about the delivery?
Checking on a lost package
Answer: Didn't the driver deliver the parcel this afternoon?
Show the answer
Answer: Didn't the driver deliver the parcel this afternoon?
The helper did marks the past, so deliver stays plain.
Question 2 of 3
Your friend asks: 'Haven't you visited that new museum?' You have never been there. Choose the short answer.
Talking about a new museum
Answer: No, I haven't.
Show the answer
Answer: No, I haven't.
The question starts with have, so the short answer uses have.
Remember this
Match the helper and the verb form. Be builds continuous and passive forms; have builds perfect forms. After do, does, or did, keep the main verb in its base form. Listen for these patterns in the recordings.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Auxiliary verbs: use be, do, and have"
Can be, do, and have be main verbs too?
Yes. Their job depends on the sentence. Be can link a subject to a description, while do can name an action and have can express possession. As helpers, they work with another verb to build a verb form.
She has a small garden behind her house.
She has planted six roses there.
Why do we use a base verb after did?
Did already marks the past tense, so the main verb stays in its base form. The same pattern applies after didn't. Do and does also take a base verb.
Did your brother find his wallet under the sofa?
Does have always describe something that has finished?
No. Have with a past participle makes a perfect form. The present perfect can describe a past event with a present connection or a situation that began earlier and continues now. Words such as for and since can help show the time period.
We've owned this small shop for nine years.
Does every question need an auxiliary verb?
No. In an affirmative subject question, who or what can take the place of the subject without adding do. Main-verb be also makes questions without do. Other question patterns may need an auxiliary or a modal such as can.
Who broke the blue vase?
Is this seat free?
How do I answer a negative yes-or-no question?
Answer according to the positive fact. If you do enjoy swimming, yes is the right choice even when the question starts with don't. Use the matching helper in a short answer; use no with the negative helper when the positive fact is false.
Don't you enjoy swimming in the sea?
Yes, I do. The water feels lovely in summer.