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.

Infinitives Part 2

Commonly, an infinitive is used with the subject it. The sentence structure is "It is                      + infinitive.…" It refers to the infinitive. This expression is used in many ways.

• It is time to do math.
• It is common to think that way.
• It is appropriate to keep a low profile.
• It was nice to see you.
• It was my pleasure to meet you.
• It was my honor to have dinner with you.
• It is good to see you.
• It was great to go on a trip with them.

Both gerunds and infinitive phrases can function as nouns, in a variety of ways. Gerunds and infinitives can follow certain verbs but not others. You need to remember which verbs can be followed by only a gerund or only an infinitive.

Verbs that can precede only gerunds:
consider, suggest, enjoy, deny, avoid, miss, mind, practice, postpone, resist, finish, quit, give up, put off

Verbs that can precede only infinitives:
offer, decide, hope, attempt, promise, agree, afford, deserve, refuse, undertake, learn, fail, seem, appear, tend, pretend, choose, demand, desire, guarantee, claim, manage, determine, expect, want, wish

Verbs that can precede either gerunds or infinitives without changing meanings:

continue, like, love, begin, start, propose, neglect, stand, hate

Verbs that can precede either gerunds or infinitives but change meanings:

forget, remember, stop, try

• I stopped watching the movie. (I no longer watched the movie.)
• I stopped to watch the movie. (I stopped what I was doing to watch the movie.)

Infinitives Part 1

An infinitive is a verb combined with the word to. Most often, an infinitive acts as a noun in the sentence. Less frequently, it acts as an adjective or an adverb.

• I want to go home early today.
• I hope to be chosen as a member.
• I prefer to go there earlier.
• You need to consider various rules in writing sentences.
• You have to explain your reasoning in detail.
• You might wish to act as a teacher.
• To leave for a vacation is my only wish at this time.
• A common mistake in a relationship is not to trust the other person.
• Help me to save the trees!
• To be mentally healthy, you must read books.
• Do you want me to fill out this form?
• Here is our to-do list.
• It was nice to meet you.
• It is time to move on.
• I am young enough to change my habits.
• Don’t forget not to make grammar mistakes.
• You are required to leave all your belongings here.
• I came to see a doctor today.
• You have to work harder to succeed.
• I need to take three more classes to finish my graduate study.
• I got closer to the speaker to listen clearly.
• Be sure to check if you have tickets.
• I am going to buy the new computer.

Generally, it is not common to split to and the verb except for when you want to emphasize the verb.

• I want you to immediately stop doing that.
• You have to seriously work hard to succeed.
• You need to definitely explain your reasoning in detail.