An infinitive is a special type of a verb. It has no person, no number, no mood and no tense.
There are two kinds of infinitives:
•The full infinitive (to-infinitive)
This infinitive has the word "to" at the beginning.
•He pretended to have seen the film.
•I want to sing.
•I had to go.
•The bare infinitive (zero-infinitive)
This infinitive has not the word "to".
•I would rather visit Rome.
•She can't speak to you.
•You made me love you.
There are 7 types of infinitives in English
1. simple infinitive
•I would like to meet the manager.
•Is there anything to eat?
•The main thing is to stay calm.
2. progressive infinitive
The progressive infinitive is used to suggest that actions and events are/were/will be continuing around the time we are talking about.
•I happened to be waiting for the bus when the accident happened.
•You must be joking.
3. perfect infinitive
Perfect infinitives can have the same kind of meaning as perfect tenses or past tenses.
•I am happy to have left school.
(= I am happy that I have left school.)
•You seem to have annoyed him.
(= It seems that you have annoyed him.)
•It is nice to have finished work.
(= It is nice that I have finished work.)
4. prefect progressive infinitive
•We have been waiting for ages.
•How long have you been living here?
•You have to have been working for the same employer for two years.
•It doesn't seem to have been working since last october.
5. simple passive infinitive
Passive infinitives have the same kind of meaning as other passive forms.
•Everybody needs to be loved.
•There is a lot of work to be done.
•She ought to be told about it.
6.progressive passive infinitive
•I seem to be being billed while Instance stopped.
•The dishes are going to be being washed by John.
•When is the film how to be being put on release?
7. perfect (progressive) passive infinitive
Perfect passive infinitives are also common.
•They were lucky they could have been killed.
•My life is blessed to have been touched by her.
•I feel so lucky to have been touched by your hands.
•The mural is going to have been being painted by the famous artist for over six months.
Negative Infinitives are normally formed by putting "not" before the infinitive.
•I decided to invite them. (affirmative)
•I decided not to invite them. (negative )
•You were silly not to have locked the car.
The marker "to" is normally used before infinitives. Note that this "to" is not a preposition; after the preposition "to" we use "-ing" forms.
The full infinitive has many functions.
1.Infinitive as subject
An infinitive can be the subject of a sentence. This was fairly common in older English.
•To err is human, to forgive divine.
•To find fault with others is easy.
In modern English, this is unusual.
We more often use it as a "*preparatory subject"( anticipatory subject), and put the infinitive clause later.
•It is human to err.
•It is easy to find fault with others.
a preparatory subject (anticipatory subject) is a subject in a sentence that serves no other purpose than to rearrange the word order and does not refer to anything by itself.
2.Infinitive as object
Many verbs can be followed by an infinitive clause in the place of the direct object.
•She wants some exercise. (noun object)
•She wants to dance. (infinitive object)
•I don't want to go to bed.
3.Infinitive clause as complement
An infinitive clause can be used after "be" as a subject complement.
•The best thing to do now is to vanish.
•You are to sit in that corner and keep quite.
•The main thing is to stay calm.
The full infinitives can be used as the object or complement of a verb, adjective or noun.
•You have the right to remain silent.
•She was anxious to contact her husband.
•That was a sight to see.
•Automation has come to stay.
•It is time to go.
In grammar the term complement is used with different meanings. The primary meaning is a word, phrase or clause which is necessary in a sentence to complete its meaning. We find complements which function as an argument (i.e. of equal status to subjects and objects) and complements which exist within arguments.
An infinitive can have its own subject. The subject of the infinitive is normally introduced by "for".
·I will be happy to help you. (I will help you.)
·I will be happy for him to help you. (He will help you.)
·My idea was to study medicine. (= I wanted to study medicine.)
·My idea was for him to study medicine. (= I wanted him to study medicine.)
The structure "for" + object + infinitive is common after adjectives, nouns and verbs.
It is used when we are referring to possibility, necessity or frequency, when we are expressing wishes, suggestions or plans for the future, and when we are giving personal reactions to situations.
·It is important for the meeting to start on time.
·His idea is for us to travel in separate cars.
·I am anxious for the party to be a success.
A for-structure is often used after "too" and "enough".
·The tea was too hot for me to drink.
·The bag was too heavy for me to lift.
·It is now too late for us to begin the new lesson.
·I explained enough for her to understand what was happening.
The for-structure can be the subject of a clause.
·For us to fail now would be a disaster.
However, it is more common for a structure with preparatory it to be used.
·It would be a disaster for us to fail now.
Instead of the "for"-structure, a "that"-clause with should or a subjunctive is often possible.
·It is important that the meeting should start on time.
·I am anxious that the party should be a success.
·His idea is that we should travel in separate cars.
As modifier of a noun
· The full infinitive can be used to modify a noun or indefinite pronoun ( nothing, something, etc.) The full infinitive comes after the noun or pronoun it modifies.
·The full infinitive shows how the noun or pronoun is to be used.
·I have work to do.
·Do you need a book to read?
·She gave him something to drink.
·They don't want anything to eat.
·There is a plan for Alice to spend a year in China.
·Is there anything for me to do?
·Is there anybody for Alice to play with?
Nouns that can be followed by infinitives
Many nouns can be followed by an infinitive complement.
·That was a sight to see.
·You have every reason to be happy.
An infinitive can be used after a noun, or an indefinite pronoun such as "something", "anything", to explain the purpose of a particular thing.
·We need fire to cook food.
·That is something to remember.
·I would like something to eat.
·I need some books to read.
·We are looking for a place to live in.
As modifier of an adjective
The full infinitive can be used to modify an adjective. The full infinitive comes after the adjective it modifies.
·Danny is happy to help Joey.
·The lessons are easy to understand.
·It's nice to see you.
·I was stupid to trust him.
·You are welcome to stay as long as you like.
Infinitive with its own subject after adjective
The structure for + object + infinitive is common after certain adjectives which expresswishes and other personal feelings.
·I am anxious for him to get a good job.
·We are delighted for them to come and stay.
·She is eager for us to see her work.
With preparatory it
"For-structures" with preparatory it are common with many adjectives expressing possibility, necessity, importance, urgency, frequency and value judgments.
·It is important for the party to be a success.
·It is not necessary for you to wait any longer.
·It is essential for them to earn while they learn.
·I thought it strange for her to be out so late.
·It isn't easy for me to let him go.
·It would be risky for you to attempt it.
·It would be dangerous for them to indulge in such activities.
Adjectives that can be followed by infinitives
Infinitives are often used after adjectives which express people's reactions and feelings. Common examples are: pleased, glad, surprised, happy, anxious, shocked, afraid etc.
·She was anxious to go home.
·I was surprised to get her letter.
·It is nice to talk to you.
·I am glad to meet you.
·You don't look happy to see me.
Other adjectives that can be followed by infinitives include: right, wrong, stupid, certain, welcome, careful, due, fit, able, likely and lucky.
·I was stupid to trust him.
·They are certain to win.
·You are welcome to stay as long as you like.
An infinitive can be used after adjective + noun to make a comment or judgment.
·It was a stupid thing to do.
·It was an astonishing way to behave.
Superlative adjectives can be followed by an infinitive structure.
·He is the oldest athlete ever to win an Olympic gold medal.
This structure is also common with first, second, third etc., next, last and only.
·Who was the first woman to climb Mt Everest?
·She is the only scientist to have won three Nobel prizes.
As Modifier of a Verb
1. The full infinitive can modify a verb or verb phrase. The full infinitive comes after the verb it modifies.
2. The full infinitives indicates purpose or intention. The idea of purpose may be emphasized by using "in order" or "so as" before the full ifinitive.
·She came to the city so as to look for work. ·He raised his voice so as to be heard. ·Joey went for Danny to get car.
·Jesse was riding fast to be on time.
·Steph came to help Michelle.
·Joey borrowed Jesse's bike to go to her house.
·DJ went in order to get her bike.
·Jesse was riding fast in order to be on time.
Before a negative infinitive, we normally use "so as" or "in order".
·I am leaving now so as not to be late.
(NOT I am leaving now not to be late.)
Infinitive with its own subject after verbs
Certain verbs are normally followed by for. Examples are: ask, hope, wait, look, pay, arrange etc.
We can use infinitives after them.
·I can't wait for them to finish talking.
(NOT I can't wait them to finish talking.)
·Can you arrange for the goods to be delivered soon?
(NOT Can you arrange the goods to be delivered soon.)
·I arranged for her to have violin lessons.
(NOT I arranged her to have violin lessons.)
Certain verbs like suit, take etc., can also be followed by a for-structure.
·It only takes ten minutes for me to walk to the office.
·Will it suit you for us to call on Sunday?
Note that a for-structure cannot be used in object position after verbs.
·I requested her to help me.
(NOT I requested for her to help me.)
·She wanted me to clear her doubts.
(NOT She wanted for me to clear her doubts.)
Verbs that can be followed by infinitives
Many verbs can be followed by the infinitives of other verbs.
·I failed to understand his motive.
·You should learn to say no.
·He agreed to come.
·He tried to open the door.
·We decided to continue our journey.
·She promised to come.
Common verbs that can be followed by infinitives are given below.
afford, agree, appear, arrange, ask, attempt, beg, begin,
care choose, consent, continue, dare, decide, except, fail
forget, happen, hate, help, hope, intend, learn
like, love, manage, mean, neglect, offer
prefer, prepare, pretend, promise
propose, refuse, regret, remember, seem
start, swear, trouble, try, want, wish
Verb + Object + Infinitive
advise, allow, ask, beg, cause, command, compel
encourage, expect, forbid, force, get, hate, help
instruct, intend, invite, leave, like, love
mean, need, oblige, order, permit, persuade, prefer
recommend, remind, request, teach, tell, trouble, want, warn
·I want her to clear my doubts.
·They don't allow people to smoke in their home.
·I told him to leave.
Points to be noted
1. Some verbs (let, make, see, feel, watch, notice, have, and sometimes know and help) are followed by object + infinitive without to (bare infinitive).
·I heard her open the door.
·We watched them play.
·Let me explain.
2. Some verbs cannot be followed by object + infinitive. "Suggest", for example, is followed by a "that-clause".
·I suggested that he should consult a doctor.
(NOT I suggested him to consult a doctor.)
3. Many of the verbs listed above can also be followed by "an -ing form (gerund)" or "a that-clause".
·Can you teach me to paint?
·Can you teach me painting?
·They stopped to talk.
·They stopped talking.
4. Many of the verbs given above can be used in passive structures with infinitives.
·They encouraged me to make another attempt. (Active)
·I was encouraged to make another attempt. (Passive)
·They requested him to help them. (Active)
·He was requested to help them. (Passive)
·They ordered her to give the money back. (Active)
·She was ordered to give the money back. (Passive)
Some verbs, however, can be used with infinitives in active structures but not passives.
Examples are: like, dislike, love, hate, prefer, wish and verbs with similar meanings.
·She likes people to be happy.
(NOT People are liked to be happy by her.)
·I hate to work on Sundays.
(NOT To work on Sunday is hated by me.)
As Modifier of a wh- word (what, how, when etc..)
1. The full infinitive may also modify a wh- word. (e.g. how, when, etc.), or wh- phrases (e.g. what time, which book, etc.)
·I am wondering how to get my bike.
(=I am wondering how I should get my bike)
·He didn't know what time to come.
(=He didn’t know what time he should come.)
Infinitives are generally used with the marker to. But we use the infinitive without "to"(bare infinitive) in some cases.
1. After modal auxiliary verbs
After the modal auxiliary verbs will, shall, would, should, can, could, may, might andmust, we use the infinitive without to.
•I shall write to him. (NOT I shall to write...)
•We can manage it. (NOT We can to manage...)
•I will say what I like.
•We must get someone to paint the roof.
•Can you help us?
The infinitive without to can also be used after "need" and "dare" in some cases.
•You need not make such a fuss over it.
•How dare you call me a liar?
After "do", we use the infinitive without to.
•Do you think she is ready?
•I do admit that I was wrong.
3.After certain principal verbs like let, make, see etc.
After certain verbs like bid, watch, see, let, make and hear, infinitives are used without to.
•They made me wait. (NOT They made me to wait.)
•He bade me come. (NOT He bade me to come.)
•I saw her light the lamp. (NOT I saw her to light...)
•We heard her sing a song. (NOT We heard her to sing...)
•We watched them play.
•Let him go.
"Help" can also be used in this way.
•She helped the child (to) lift the box.
In passive versions of these structures the infinitive is used with to.
•She was heard to sing a song.
•He was helped to lift the box.
•She was made to pay back the money.
4.After "rather", "better" and "had better"
After rather, better and had better, we use the infinitive without to.
•You had better consult a doctor.
•I would rather go alone.
•He would rather die than yield to pressure.
5.After and, or, except, but, than, as and like
When two infinitive structures are joined by and, or, except, but, than, as or like, the second is often without to.
•It is as easy to smile as frown.
•Do you want to have lunch now or wait till later?
•We had nothing to do except look at the cinema posters.
6.After why (not)
We can introduce questions and suggestions with why (not) + infinitive without to.
•Why stand up if you can sit down?
•Why pay more at other shops? We have the lowest prices.
•Why not make it up with him?
Note that no noun or pronoun should come after why (not).
•Why not arrange a party in his honour?
(NOT Why not we arrange a party in his honour?)