The infinitive also represents the action without referring to a person or number. These are the verb properties of the infinitive: to have a direct object; to be modified by the adverb.

It is a non-finite verb form, which means it does not have a specific tense or subject-verb agreement.

The infinitive is often introduced by the word to, but it can also be used without it in certain contexts.

For example, Let’s eat pizza uses the infinitive eat without to.

The infinitive can be used in both active and passive voice sentences.

For example:

I want to write a book is active voice, while

To be loved by all is a dream, is passive voice.

The infinitive can function as the subject, object, adjective, or adverb of a sentence.

For example:

To swim in the ocean is my favourite activity. (subject)

She likes to sing. (object)

I need a pen to write with. (adjective)

She runs to stay fit. (adverb)

The infinitive has properties of both a verbal noun and the verb.

Like a noun, it can function as the subject or object of a sentence, or it can be used as an adjective or adverb.

But like a non-finite verb, it doesn’t have a specific tense or subject-verb agreement.

This flexibility is what makes the infinitive such a useful and versatile part of English grammar. It can be used with tense forms and voices.

The forms of the infinitive:

Indefinite Infinitive active:

To form the indefinite infinitive active, we use the base form of the verb preceded by to.

For example: to swim, to run, to read.

Continuous Infinitive active:

To form the continuous infinitive active, we use to be, followed by the present participle of the verb.

For example: to be swimming, to be running, to be reading

Perfect Infinitive active:

To form the perfect infinitive active, we use to have in the present tense, followed by the past participle of the verb.

For example: to have swum, to have run, to have read,

Perfect Continuous Infinitive active:

To form the perfect continuous infinitive active, we use to have been in the present tense, followed by the present participle of the verb.

For example: to have been swimming, to have been running, to have been reading.

Indefinite infinitive passive:

To form the indefinite infinitive passive, we use to be, followed by the past participle of the verb.

For example, to be asked, to be written, to be shown.

Perfect infinitive passive:

To form the Perfect Infinitive passive, we use to have been in the present time, followed by the past participle of the verb.

For example, to have been asked, to have been written

When the infinitive is used in the indefinite form (also known as the simple form) and perfect form, it can express different meanings.

Indefinite (simple) Infinitive:

The indefinite (simple) infinitive, which is formed using to plus the base form of the verb, is used to express a general idea or purpose.

It can be used as a noun, an adjective, or an adverb.

For example, To learn a new language is challenging.

(The infinitive to learn is used as a subject to express a general idea.)

He has a book to read.

(The infinitive to read is used as an adjective to describe the book.)

She walked to the store to buy some groceries.

(The infinitive to buy is used as an adverb to show the purpose of the action.)

Perfect Infinitive:

The perfect infinitive, which is formed using to have plus the past participle of the verb, is used to indicate that an action was completed before another action or point in time.

It can be used to show cause-and-effect or to express regret, among other meanings.

For example, He seems to have forgotten his promise.

(The perfect infinitive to have forgotten indicates that the action of forgetting was completed before the present moment.)

She appears to have finished her work.

(The perfect infinitive to have finished indicates that the action of finishing was completed before the present moment.)

Bare Infinitive:

After modal verbs such as must, may, should, and ought to, and after certain verbs like expect, intend, hope, and want, the base form of the verb (infinitive) can be used to express future actions.

This is often called the bare infinitive.

Here are some examples:

I must study for the exam tomorrow.

She may come to the party later tonight.

You should exercise regularly to stay healthy.

We ought to take the train instead of driving in this traffic.

I expect to finish my work by the end of the day.

She intends to start her own business next year.

I hope to travel to Europe someday.

They want to buy a new house in the near future.

In each of these examples, the base form of the verb is used to indicate a future action that is expected, intended, or desired.

The continuous infinitive and the perfect continuous infinitive are not commonly used in English, and may sound awkward or unusual in most contexts.

However, here’s a brief explanation of what they express:

Continuous Infinitive:

The continuous infinitive, which is formed by using to be plus the present participle of the verb, can be used to express ongoing action or continuous progress.

It is not used very often, but it might appear in some formal or literary contexts.

Here’s an example: His dream is to be travelling the world, experiencing new cultures and meeting new people.

(The continuous infinitive to be travelling expresses ongoing action or a continuous process.)

Perfect Continuous Infinitive:

The perfect continuous infinitive, which is formed by using to have been plus the present participle of the verb, can be used to express a continuous action that started in the past and is still ongoing at the present time.

Again, this is not a common construction in English, but here’s an example: She seems to have been studying for hours without taking a break.

(The perfect continuous infinitive to have been studying expresses a continuous action that started in the past and is still ongoing.)

The particle to + the infinitive:

In English, the infinitive can be used with or without the particle the particle with the infinitive:

The particle to is always used before the infinitive in its simple form, as in to go, to eat, to read, etc.

The particle to is usually omitted after modal auxiliary verbs such as can, could, may, might, shall, should, will, and would.

For example, She can swim.

(Not She can to swim.)

We should leave now.

(Not We should to leave now.)

They will arrive soon.

(Not They will to arrive soon.)

The particle to is not generally used after verbs of perception and causation, such as: see, hear, feel, make, help, and let.

For example, I heard her sing. (Not I heard her to sing.)

He made me laugh. (Not He made me to laugh.)

Let me go early. (Not She let me to go early.)

In some cases, the infinitive can be used with or without the particle to without any significant difference in meaning.

For example, I want to eat pizza. (With to)

I want pizza. (Without to)

The infinitive with the particle to can be used after a wide variety of verbs in English.

The infinitive with to:

Agree: I agreed to help with the project.

Decide: She decided to take a year off from work.

Offer: They offered to pay for our dinner.

Refuse: He refused to apologise for his behaviour.

Promise: She promised to meet us at the restaurant.

Learn: He wants to learn to play the guitar.

Manage: We managed to finish the project on time.

Attempt: She attempted to climb the mountain, but turned back due to bad weather.

Need: I need to buy some groceries.

Wish: I wish to see the Eiffel Tower someday.

Note that this is not an exhaustive list, and there are many other verbs that can be followed by the infinitive with to.

The main functions of the infinitive:

As the subject of a sentence:

To travel is my greatest passion.

In this sentence, the infinitive to travel acts as the subject of the sentence, and it tells us what the speaker’s greatest passion is.

As a part of the nominal predicate:

Her dream is to become a pilot.

In this sentence, to become a pilot acts as part of the nominal predicate. It describes what her dream is, and it functions as a complement to the subject Her dream.

As a part of the verbal predicate:

She wants to study abroad.

In this sentence, wants to study acts as part of the verbal predicate. It describes what she wants to do, and it functions as the object of the verb wants.

As an object:

He likes to play the guitar.

In this sentence, to play the guitar functions as the direct object of the verb likes. It describes what he enjoys doing.

As an attribute:

Her dream, to travel the world, seemed unattainable.

In this sentence, to travel the world serves as an attribute to the noun dream. It adds more information about her dream, describing what it entails.

As an adverbial modifier:

She woke up early to catch the first train.

In this sentence, to catch the first train acts as an adverbial modifier that explains the purpose or reason for her waking up early. It provides additional information about the action of waking up.

The infinitive possesses the properties of the verb: takes a direct object and is used with adverbs and in tense forms and voices:

She wants to buy a new car.

In this sentence, the infinitive to buy takes the direct object a new car. The infinitive to buy represents the action she desires to perform, and the direct object a new car specifies what she wants to buy.

He decided to carefully paint the beautiful artwork.

In this sentence, to carefully paint is the infinitive phrase, and carefully is the adverb that modifies the infinitive. It describes how he will perform the action of painting the beautiful artwork.

The construction: for+noun/pronoun+infinitive:

The action of the infinitive performed by a person or thing can be expressed by the noun in the common case and the pronoun in the object case.

This construction consists of: for+ a noun in the common case and a pronoun in the object case + infinitive.

This construction functions in a sentence as a complex subject, a complex attribute, a part of a complex nominal predicate, and a complex adverbial modifier.

Here are some examples of the various functions of the infinitive in the construction for + a noun/pronoun + infinitive:

Compound Subject:

For John and Mary to arrive early would be a good idea.

(For John and Mary to arrive early is the compound subject of the sentence.)

For him and his colleagues to complete the project on time is imperative.

(For him and his colleagues to complete the project on time is the compound subject of the sentence.)

Compound Object:

We need to prepare the room for the guests to stay overnight.

(The room is the object of prepare, and for the guests to stay overnight is the compound object.)

She asked him for some advice on how to solve the problem. (Him is the object of asked, and for some advice on how to solve the problem is the compound object.)

Compound Part of the Nominal Predicate:

Our plan is for us to work together to achieve our goals.

(For us to work together to achieve our goals is a compound part of the nominal predicate our plan is.)

The decision is for the committee to make, not for me.

(For the committee to make is a compound part of the nominal predicate the decision is.)

Compound Modifier:

She bought a dress for her daughter to wear to the wedding.

(For her daughter to wear to the wedding is a compound modifier describing dress.)

He gave her a book for her to read during her vacation.

(For her to read during her vacation is a compound modifier describing book.)

In each of these examples, the infinitive phrase after for serves a different function in the sentence.

The objective with the infinitive construction:

The objective with the infinitive construction is used when an action is the object of a verb and the action is expressed in the form of an infinitive verb phrase. This construction acts as a complex object of the sentence.

This construction is used with verbs expressing wish: want, wish, should/would like, desire, like, and hate.

The structure of this construction is:

subject + verb + object + infinitive phrase (to + base form of the verb).

Examples:

I want him to learn how to play the guitar.

She wished the homework to be finished before going out.

He desired a promotion to be given soon.

If the action performed by the infinitive refers to the subject of the sentence, do not use the pronoun before the infinitive:

I would like to be invited to the party.

They do not like to be asked about it.

In each of these examples, the infinitive phrase following the verb serves as the complex object of the sentence.

So, the to particle is necessary to form the to-infinitive, and it is used in this construction.

When using the objective with the infinitive construction after verbs of perception such as: see, watch, observe, hear, feel, and notice, the infinitive is used without the particle to.

For example, She saw him leave the room.

(Leave is the bare infinitive used as the object of the verb saw.)

He heard her sing a song.

They noticed him enter the building.

In these cases, the bare infinitive (without the particle to) is used instead of the to-infinitive.

This is a common usage in English grammar.

After verbs of perception such as: see, watch, observe, hear, feel, and notice, the passive infinitive is not commonly used in the objective with the infinitive construction.

Instead, the bare infinitive is usually used.

For example, She saw him leave the room.

(bare infinitive leave)

He heard her sing a song.

(bare infinitive sing)

They felt the ground shake.

(bare infinitive shake)

However, there are some cases where the passive infinitive can be used after verbs of perception, but it is less common and has a different meaning.

In these cases, the passive infinitive is used to show the result of the action of the main verb.

For example, She was heard to sing a beautiful song.

(passive infinitive: to sing)

The building was observed to be on fire.

(passive infinitive: to be on fire)

In these examples, the passive infinitive is used to show the result of the action, rather than the action itself.

But as mentioned earlier, the bare infinitive is more commonly used after verbs of perception in the objective with the infinitive construction.

Instead of using the objective with the infinitive construction after verbs like see and notice, you can use a subordinate clause with the conjunction that.

For example, She saw that he left the room.

(subordinate clause that he left)

They noticed that the door was open. (subordinate clause that the door was open)

In these examples, the subordinate clause functions as the object of the verb saw and noticed, instead of using the infinitive construction.

This construction is commonly used in formal writing and speech, and can sometimes be preferred over the infinitive construction for clarity or emphasis.

When the verbs to hear and to see are used in a sense that does not express perception

(i.e., when they are used to mean to learn of or to find out), the objective with the infinitive construction is not typically used.

Instead, a subordinate clause introduced by that can be used as the object of the verb.

For example, I heard that she got a promotion.

(subordinate clause that she got a promotion)

He saw that the car was damaged.

(subordinate clause that the car was damaged)

In these examples, the subordinate clause functions as the object of the verb heard and saw, instead of using the infinitive construction.

The objective with the infinitive construction is commonly used after verbs of assumption like: to believe, to suppose, to consider, to know, to expect, to think, to find, and to declare,

when the infinitive is preceded by the particle to.

For example: I believe him to be honest.

She considered it to be a waste of time.

They expect us to arrive on time.

He declared the meeting to be over.

In these examples, the infinitive construction to be honest, to be a waste of time, to arrive on time, and to be over functions as the object of the verb: believe, consider, expect, and declare, respectively.

In the examples, the infinitive to be is used as a copula, linking the subject of the sentence to a complement that describes or identifies it.

For example, in the sentence:

I believe him to be honest, the infinitive to be honest is a complement that describes the subject him.

Similarly, in the sentence, She considered it to be a waste of time, the infinitive to be a waste of time is a complement that describes the subject it.

The copula to be can be omitted in some cases, especially in informal or spoken language.

For example, instead of saying I consider him to be a good candidate, you might hear someone say I consider him a good candidate.

However, in more formal writing or in contexts where precision is important, it’s generally better to include the copula to be.

When the verb expect is used in the objective with infinitive construction, the passive infinitive is used to indicate the action that is expected.

For example, consider the sentence:

I expect the report to be completed by Friday.

In this sentence, the report is the direct object of the verb expect, and to be completed by Friday is the passive infinitive that describes the action that is expected to take place.

The passive infinitive to be completed indicates that the report is not completing the action, but rather that the action is being done to the report by someone else.

The Objective with the Infinitive Construction with Verbs:

to rely on, to count upon, to wait for:

Here are sentences using the verbs to rely on, to count upon, and to wait for, followed by infinitive constructions:

You rely on your team to finish the project on time.

He always counts upon his best friend to support him in difficult times.

We can’t wait for the concert to start; the band is famous for their amazing performances.

The infinitive with common verbs:

Here’s a list of some common verbs that are typically followed by an infinitive, along with examples:

Want

I want to travel around the world.

She wants to learn a new language.

Need

He needs to finish his homework.

We need to buy some groceries.

Hope

They hope to win the competition.

She hopes to get a promotion.

Plan

We plan to go hiking this weekend.

He plans to start a new business.

Decide

She decided to go to the concert.

They decided to move to a different city.

Intend

They intend to visit their grandparents.

He intends to study medicine.

Like

I like to play the guitar.

She likes to read books.

Love

He loves to play football.

They love to watch movies.

Hate

She hates to wake up early.

I hate to see people suffer.

Prefer

We prefer to eat at home.

He prefers to walk instead of taking the bus.

Agree

They agreed to help with the project.

She agreed to meet him later.

Refuse

He refused to apologise.

They refused to attend the meeting.

Promise

She promised to call me later.

They promised to support the cause.

Attempt

He attempted to climb the mountain.

She attempted to solve the puzzle.

Learn

We learn to improve ourselves.

He learned to play the piano.

Struggle

They struggled to find a solution.

She struggled to overcome her fears.

Begin

He began to study for the exam.

They began to build their dream house.

Continue

She continues to work on her thesis.

They continued to search for the missing item.

Start

He started to run the marathon.

We started to organise the event.

Fail

They failed to reach the summit.

She failed to pass the driving test.

Please note that some verbs may have multiple patterns of usage, and context can sometimes affect which construction is appropriate.

However, these examples should give you a good starting point for verbs that are commonly used with an infinitive.

The Objective with the Infinitive with Verbs: to ask, to order, to command, and to allow:

The objective with the infinitive construction can be used with verbs that convey the idea of order, command, allowance, and request. In this construction, the main verb is followed by the word to and then an infinitive verb. The objective with the infinitive after these verbs is used in the passive voice, and for preposition after the verb ask is added.

She ordered him to be ready till she returned.

The teacher commanded the students to be quiet during the exam.

The student asked for the homework to be explained for once more.

The parents allowed their children to be examined by the doctor.

The Infinitive-Non-Finite form of the Verb

The Imperative Mood

The Subjunctive Mood

The Sequence of Tenses

The Indicative Mood – the Active Voice- Finite forms of the Verb

The Indicative Mood-the Passive Voice

The Group of Tenses of the Passive Voice

The Past Perfect tense