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.

"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.

"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?

"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.