ref – https://www.grammarly.com/blog/auxiliary-verbs/

Helping verb AKA Auxiliary verbs

are minor verbs that support the sentence’s main verb

primary auxiliary verbs

be (continuous tense):

The continuous tenses use a conjugated form of the auxiliary verb be along with the present participle (-ing form) of the main verb.

I am [work]ing in the shed.

She was [study]ing all night.

They will be [sleep]ing when you arrive.

She is (aux verb) walking (main verb) home.
It was (aux verb) raining (main verb) heavily last night.

Perfect tenses (have)

The perfect tenses use a conjugated form of the auxiliary verb have along with the past participle form of the main verb.

They have just finished class and are getting ready for recess.
I had forgotten about the birthday party until I saw the calendar.
By the time you get off work, the movie will have started already.
We have (aux verb) been (main verb) to India.
I will have (aux verb) arrived (main verb) by then.
I have (aux verb) played (main verb) since Basketball since middle school.
She(subj) has (aux verb) seen (main verb) this movie before.

More examples:

They(subj) are (aux verb) coming (main verb) with us.
The criminal was (aux verb) caught (main verb) yesterday.

Perfect continuous tenses (be and have)

The perfect continuous tenses use a conjugated form of the auxiliary verb have and the past participle of the auxiliary verb be (been) along with the present participle of the main verb. (have been + verb-ing)

I have been reading Moby Dick for months now.

He had been working there for five years before he quit.

Tomorrow, we will have been dating for an entire year.

do (emphasis):

I do (aux verb) want (main verb) dinner.
She does (aux verb) like (main verb) dancing.
I (subj) do (aux verb) enjoy (main verb) a good conversation.
She did find it!

modal auxiliary verbs

Likelihood: It might (aux verb) rain (main verb) over the weekend.
Ability: She can (aux verb) run (main verb) faster than me.
Permission: You may (aux verb) swim (main verb) in the pool.
Intention: I shall (aux verb) leave (main verb) the party early.
Request: Would (aux verb) you look (main verb) after my dog?
Necessity: He must (aux verb) remember (main verb) their anniversary.

More examples:

We should (aux verb) study (main verb) for our final exam. (necessity)
They might (aux verb) give (main verb) us a discount if we ask. (Likelihood)
I have lots of money, so I can (aux verb) afford (main verb) it. (ability)
May (aux verb) I have (main verb) a drink, please? (Request)
The class will (aux verb) bring (main verb) food tomorrow for the party. (Intention)