Infinitives are used in many structures, especially after catenative verbs. Follow the article to learn them.

What Are Infinitives in English?

What Are Infinitives?

Infinitives are non-finite structures that are usually used to express suggestions, opinions, purposes, etc. without specifying who or what is doing the action. Infinitives can be used in various grammatical constructions, such as infinitive phrases, infinitive clauses, and infinitive verbs.

Infinitives: Types

There are two main types of infinitives in English:

What Are To-infinitives?

To-infinitives, also known as full infinitives, are a type of verb form created by adding the word 'to' before the base form of a verb. They are called 'to-infinitives' because they always include the word 'to'. For example:

She wants to learn Spanish.

Here, the base form of the verb 'learn' follows 'to' and together, they form a 'to-infinitive'.

He is excited about his opportunity to travel.

Functions of To-infinitives

Infinitives are used to make infinitive clauses or phrases which can function as the subject, adverb, adjective, direct object, object of the preposition, or complement of a clause.

They like to drink a cup of tea.

They want to choose the best teacher.

'To-infinitives' can also be categorized according to their part of speech in a sentence:

  • Nominal infinitives
  • Adjectival infinitives
  • Adverbial infinitives

Nominal Infinitives

Nominal infinitives, also known as infinitive phrases, are a type of construction in which an infinitive verb form is used as a noun in a sentence. Nominal infinitives can also be modified with adjectives or adverbs, just like any other noun in the sentence.


Nominal infinitives can fulfill many grammatical functions in a sentence, such as:

  • Subject
  • Direct object
  • Object of the preposition

To speak to him required such an effort. → Subject

I want to kiss the baby. → Direct object

They have decided to fire you. I am so sorry. → Direct object

We had no choice but to cry. → Object of the preposition


Nominal infinitives as subjects can appear at the beginning of a sentence:

To become a bestselling author is my dream.

As objects, they can appear after the verbs that are catenative (verbs that need another verb as a direct object).

We all want to go to the zoo.

And also they can appear after the prepositions as the objects of that prepositions:

I had no choice but to study for my exam.

using an infinitive as an object

Adjectival Infinitives

Adjectival infinitives are a type of construction in which an infinitive verb form is used as an adjective to modify a noun or pronoun in a sentence.


They are used to provide additional information about the noun or pronoun they modify. For example:

This is a book to read.

This boy is a baby to love.


Adjectival infinitives are often used after linking verbb. As adjectives, they can appear in __two...... positions:

  • Predicative Adjectival Infinitives
  • Postpositive Adjectival Infinitives

A predicative adjectival infinitive follows a linking verb and describes the subject of the sentence. For example:

My mom's cheesecake is to die for.

A postpositive adjectival infinitive comes after the noun it modifies. For example:

It has a kitchen to die for. (postpositive)

Sometimes to-infinitives are used after wh-words to ask for or to give information. Here is the structure:

I do not know how to make you happy.

They asked me what to do.

Adverbial Infinitives

Adverbial infinitives are a type of construction in which an infinitive verb form is used as an adverb in a sentence. Adverbial infinitives modify the verb in the sentence, providing additional information about the action being performed.


Adverbial infinitives are to-infinitives that function as:

The book is really easy to carry.

  • Adverbs of Reasons (answering to the question 'why')

To cook your favorite meal, we need potatoes, onions and oil.


Adverbial infinitives can appear as adjective complements after adjectives in a sentence. They do not necessarily need to immediately follow the adjective; sometimes a prepositional phrase can come before them. The structure is as follows:

  • Dummy subject + Linking verb + Adjective + (for/of someone) + (to-infinitive)

Check out the examples for more clarification:

It is important for you to learn physics at school.

It is kind of you to help the poor

As an adverb, they can appear both at the beginning and at the end of a sentence. For example:

I need to go see a dentist to have a nicer smile.

To have a nicer smile, I need to go see a dentist.

What Are Bare Infinitives?

Bare infinitives are a type of verb form that consists of the base form of a verb without the word 'to' before it. They are called 'bare' infinitives because they are not preceded by the word 'to'. Here are a few examples:

They helped rescue the dog.

Help me pack my stuff.

Placement and Functions

Verbs of perception that are followed by a direct object (whether a noun or pronoun) are often used with a bare infinitive as an object complement. The structure of such a clause is as follows:

  • Subject + Verb of perception + Direct object + Object complement

Here are a few examples:

Those girls saw us kidnap the boy.

I heard her lie about the murder.

We use a bare infinitive after 'why' to make a suggestion. Here are a few examples:

Why not leave without him?

Why stay outside and wait for Marco?

Why not have salmon?

Infinitives in Passive Formation

To form an infinitive in the passive voice, you can use the to-infinitive form of the verb 'be' followed by the past participle form of the main verb. Here are a few examples:

There are exercises to be done.

The cat needs to be fed three times a day.

Present Perfect Tense of the Infinitives

The present perfect tense can be formed using infinitives in English. To do so, you can use the to-infinitive form of the verb 'have' followed by the past participle form of the main verb. Here are a few examples:

It is nice to have done all the chores.

They wanted to have finished the project by Thursday.

Prepositional Phrase vs. Infinitive Phrases

Both prepositional phrases and infinitive phrases can begin with 'to'. The key difference between these two is that prepositional phrases are nouns, pronouns, or nominal structures governed by the preposition 'to,'; however, infinitive phrases are verbs or verbal structures governed by the particle 'to.' Pay attention to the examples:

The blind man wants to meet the king. → Infinitive phrase

Give the keys to my roommate. → Prepositional phrase


Sometimes the preposition 'to' is used to express purpose, in which case it is followed by the base form of the verb, just like to-infinitives. However, the difference is that the preposition 'to' forms a prepositional phrase that acts as an adverb of purpose. One way to distinguish between the infinitive marker 'to' and the preposition 'to' is to check if you can change the place of clauses in the sentence. In sentences with to-infinitives clauses cannot change place. Compare the examples:

I am going to work out today. → to-infinitive

you can't say 'To work out today I am going.'

I work out every day to stay fit → preposition of purpose

You can say 'To stay fit, I work out every day'.


Some verbs can be used with both bare infinitives and to-infinitives. Check out the examples:

They helped to save the dog.

They helped save the dog


Infinitives are categorized into three main groups:

  1. Nominal infinitives
  2. Adjectival infinitives
  3. Adverbial infinitives

There are two types of infinitives in English:

  1. To-infinitives
  2. Bare infinitives


Loading recaptcha

You might also like

Present Participles

Present participles are one of the key features of English language. It is a form of verb that ends in '-ing.' In this lesson, we will learn more about them.

Past Participles

The past participle is the third principal part of a verb that is most commonly known to be used with tenses. In this lesson, we will learn all about them.

Perfect Participles

A perfect participle is a participle that is used with an auxiliary verb to imply a special meaning. In this lesson, you will learn about perfect participle.


To-infinitives are the base form of the verbs preceded by the preposition 'to'. To-infinitives are used in many conditions. In this lesson, we will learn them.

Bare Infinitives

The word 'bare' means without the addition of something. So you can easily get the meaning of a bare infinitive.

Infinitive Clauses

To learn infinitive clauses, first of all, you should know the elements in a cause and the definition of an infinitive. In this lesson, we will learn them.
Download LanGeek app