What is an Infinitive?

The Infinitive is a non-finite form of the verb which names an action.

As a rule the infinitive is used with the particle to.
Students go to school to get knowledge.
If two infinitives are connected by the conjunctions and or or, the particle to is placed only before the first infinitive.
Your mother wants you to come and see her.
At the end of the sentence the particle to is sometimes used without the infinitive if the infinitive is understood from the context.
Why didn’t you come? You promised to.

The Infinitive is used without to:

after modal verbs except ought, to have, to be: He can swim. You must go. May I ask you? You shouldn’t drink coke. How dare you ask me? You ought to wash. I had to send him money. We are to see her tonight.

after auxiliary verbs: I don’t speak Japanese. We will write a dictation tomorrow.

after the expressions had better, would sooner, would rather: You had better go back to your sisters. I would sooner come with you. I’d rather not talk about such things. You’d better consult the dictionary.

after causative verbs have, make, let: I won’t have him shout at me. Let’s take this book. Let her read the text. She made her brother rewrite the exercise. The teacher made them work hard.

in the Objective Infintive Complex after the verbs of sense perception: We saw him enter the house. We have never heard this girl sing. She heard the clock strike eight.

in senteces which start with Why: Why not visit them on Sunday?

The Infinitive in English has six forms:

The Simple Active Infinitive to do

The Simple Passive Infinitive to be done

The Continuous Infinitive to be doing

The Perfect Infinitive to have done

The Perfect Passive Infinitve to have been done

The Perfect Continuous Infinitive to have been doing

Reference List of Verbs Followed by Infinitives

Verbs with a bullet (•) can also be followed by gerunds.

Verbs Followed Immediately by an Infinitive

afford I can’t afford to buy it.
agree They agreed to help us.
appear She appears to be tired.
arrange I’ll arrange to meet you at the airport.
ask He asked to come with us.
can’t bear• I can’t bear to wait in long lines.
beg He begged to come with us.
begin• It began to rain.
care I don’t care to see that show.
claim She claims to know a famous movie star.
consent She finally consented to marry him.
continue He continued to speak.
decide I have decided to leave on Monday.
demand I demand to know who is responsible.
deserve She deserves to win the prize.
expect I expect to enter graduate school in the fall.
fail She failed to return the book to the library on time.
forget• I forgot to mail the letter.
hate• I hate to make silly mistakes.
hesitate Don’t hesitate to ask for my help.
hope Jack hopes to arrive next week.
learn He learned to play the piano.
like• I like to go to the movies.
love• I love to go to operas.
manage She managed to finish her work early.
mean I didn’t mean to hurt your feelings.
need• I need to have your opinion.
offer They offered to help us.
plan I am planning to have party.
prefer• Ann prefers to walk to work.
prepare We prepared to welcome them.
pretend He pretends not to understand.
promise I promise not to be late.
refuse I refuse to believe this story.
regret• I regret to tell you that you failed.
remember• I remembered to lock the door.
seem That cat seems to be friendly.
can’t stand• I can’t stand to wait in long lines.
start• It started to rain.
struggle I struggled to stay awake.
swear She swore to tell the truth.
threaten She threatened to tell my parents.
try• I’m trying to learn English.
volunteer He volunteered to help us.
wait I will wait to hear from you.
want I want to tell you something.
wish She wished to come with us.

Verbs Followed by a (pro)noun + an Infinitive

advise• She advised me to wait until tomorrow.
allow She allowed me to use her car.
ask I asked John to help us.
beg They begged us to come.
cause Her laziness caused her to fail.
challenge She challenged me to race her to the corner.
convince I couldn’t convince him to accept our help.
dare He dared me to do better than he had done.
encourage He encouraged me to try again.
expect I expect you to be on time.
forbid I forbid you to tell him.
force They forced him to tell the truth.
hire She hired a boy to mow the lawn.
instruct He instructed them to be careful.
invite Harry invited the Johnsons to come to his party.
need We needed Chris to figure out the solution.
order The judge ordered me to pay a fine.
permit He permitted the children to stay up late.
persuade I persuaded him to come for a visit.
remind She reminded me to lock the door.
require Our teacher requires us to be on time.
teach My brother taught me to swim.
tell The doctor told me to take these pills.
urge I urged her to apply for the job.
want I want you to be happy.
warn I warned you not to drive too fast.

Complete the sentences with the correct form, Gerund or Infinitive, of the words in parentheses.

Sam volunteered (bring) __________ some food to the reception.
The students practiced (pronounce) _____________ the “th” sound in the phrase “these thirty-three dirty trees”.
In the fairy tale, the wolf threatened (eat) __________ a girl named Little Red Riding Hood.
Susie! How many time do I have to remind you (hang up) ______________ your coat when you get home from school?
The horses struggled (pull) __________ the wagon out of the mud.
Anita demanded (know) __________ why she had been fired.
My skin cant tolerate (be) ___________ in the sun all day. I get sunburned easily.
I avoided (tell) ____________ Mary the truth because I knew she would be angry.
Fred Washington claims (be) ___________ a descendant of George Washington.
Mr. Kwan broke the antique vase. I’m sure he didn’t mean (do) ____________ it.
I urged Mike (return) _____________ to school and (finish) ___________ his education.
Mrs. Freeman can’t help (worry) _____________ about her children.
Children, I forbid you (play) _____________ in the street. There’s too much traffic.
My little cousin is a blabbermouth! He can’t resist (tell) ____________ everyone my secrets!
I appreciate your (take) ___________ the time to help me.
I can’t afford (buy) ______________ a new car.
Kim managed (change) _____________ my mind.
I think Sam deserves (have) ____________ another chance.
Olga finally admitted (be) ___________ responsible for the problem.
I don’t recall ever (hear) ____________ you mention his name before.
Nadia keeps (promise) _____________ (visit) _____________ us, but she never does.
Margaret challenged me (race) ___________ her across the pool.
Oscar keeps (hope) ____________ and (pray) ____________ that things will get better.
I finally managed (persuade) ______________ Yoko (stay) ___________ in school and (finfish) ____________ her degree.

Using the Simple Form after Let and Help

Let is followed by the simple form of a verb: My father lets me drive his car. I let my friend borrow my bicycle. Let’s go to the movie.

Help is often followed by the simple form of a verb: My brother helped me wash my car. An infinitive is also possible: My brother helped me to wash my car.

Complete the sentences with verb phrases.

Example: Don’t let me … – Don’t let me forget to take my keys to the house with me.