Auxiliary Verbs "Be," "Do," "Have"

An auxiliary verb helps the main (full) verb and is also called a "helping verb." With auxiliary verbs, you can write sentences in different tenses, moods, or voices. Auxiliary verbs are: be, do, have, will, shall, would, should, can, could, may, might, must, ought, etc.

I think I should study harder to master English.

I am having a cup of coffee.

You have been practicing hard.

It was written by a petitioner.

You may choose what you like.

The verb forms of be, do, and have can be used either as a main (full) verb or an auxiliary verb. The following examples show these verbs used as auxiliary verbs.

1. "Be" as an auxiliary verb

a. Used in progressive sentences:

I am taking a bath.

She is preparing dinner for us.

They have been studying all night.

b. Used in passive sentences:

I was given a free meal.

He was seen by fans at the airport.

This song has been sung by all nations.

2."Do" as an auxiliary verb

a. Used in negative sentences:

I do not know the truth.

She doesn’t agree with me.

They didn’t arrive here yet.

b. Used in questions:

Do you want to have another one?

Did he finish his homework?

Do we need to keep going straight?

3."Have" as an auxiliary verb

a. Used in perfect sentences:

I have been following you for a mile.

We have done a lot so far.

She had been queen of the town.