Infinitives in English Grammar: Meaning, Types, Uses, Examples, and Exercises

Have you ever read a sentence like ‘She wants to learn English’ or ‘They came to help’ and wondered what role the ‘to + verb’ part plays? That structure is called an infinitive. They help us express actions, intentions, purposes, and ideas clearly in sentences. Infinitives can function as nouns, adjectives, or adverbs.

In this article, you will learn what an infinitive is, the types of infinitives, the functions of an infinitive verb, infinitive phrases, differences between infinitives and gerunds, and exercises to strengthen your understanding.

Table of Contents

• What are Infinitives?
• What is an Infinitive Verb?
• Types of Infinitives
• Functions of an Infinitive Verb
• How to Use an Infinitive in a Sentence
• What is an Infinitive Phrase?
• Infinitives vs Gerunds
• Infinitives vs Prepositional Phrases
• Infinitives Examples
• Infinitives Exercises

 

What are Infinitives?

An infinitive is the base form of a verb, usually with the word to before it, such as to run, to eat, or to study. It does not show a specific tense or subject. An infinitive can be used as a noun, an adjective, or an adverb in a sentence.

Examples: 

• She decided to sleep early. 

• To succeed, you must work hard. 

• He has work to do.
  
  

What is an Infinitive Verb?

An infinitive verb is the basic form of a verb that is often preceded by 'to'. It can act as different parts of speech in a sentence, including a noun, adjective, or adverb. The infinitive verb either takes a to before the base form (full infinitive) or appears without to (bare infinitive).

It is important to note that while an infinitive contains a verb, it does not act as the verb of the sentence. The main verb is always a different word. The infinitive performs the role of a noun, adjective, or adverb instead.

Examples

• To read is my favourite hobby.

• I have a book to read.

• She works hard to succeed.

In these sentences, the infinitive performs different functions while keeping the same verb form.

 

Types of Infinitives

Infinitives are broadly classified into two types based on whether the word to precedes the verb or not.

Full Infinitive

A full infinitive, also called a to-infinitive, consists of to + the base form of the verb. It is the most common form of the infinitive and appears in a wide range of sentence structures.

Structure: to + base verb

Examples: to eat, to write, to run, to decide, to understand

• She wants to become a doctor.

• It is important to study regularly.

• He promised to call back.

Verbs commonly followed by the full infinitive: agree, appear, arrange, ask, attempt, choose, claim, decide, deserve, expect, fail, forget, hope, learn, manage, need, offer, plan, pretend, promise, refuse, seem, try, want, wish.

Bare Infinitive

A bare infinitive is the base form of the verb used without the word to. It appears most often after modal verbs such as can, will, should, must, may, might, would, and could, and after certain causative and sensory verbs.

Structure: base verb (no 'to')

Examples: eat, write, run, decide

• You should eat before the exam. (After a modal verb)

• The teacher made the students sit quietly. (After 'make')

• Let her finish her sentence. (After 'let')

Both types of infinitives can appear in the same sentence. In the sentence, “I want to see her dance,” the word want is the main verb, to see is the full infinitive, and dance is the bare infinitive.

 

Functions of an Infinitive Verb

An infinitive verb can function as a noun, an adjective, or an adverb, depending on how it is used in a sentence.

Infinitive as a Noun

When an infinitive acts as a noun, it can serve as the subject, object, or complement of a sentence. It typically answers the question ‘What?’

Examples:

As a subject: To forgive is a great virtue.  (What is a great virtue? To forgive.)

As an object: She loves to read.  (She loves what? To read.)

As a complement: His goal is to win the championship. (To win the championship complements the subject goal.)

Infinitive as an Adjective

When an infinitive modifies a noun or pronoun, it functions as an adjective. It provides more information about the noun or pronoun it follows.

Examples: 

We need someone to lead the team.  (To lead the team describes someone.)

I have a report to submit.  (To submit describes report.)

She gave me a book to read. (To read describes book.)

Infinitive as an Adverb

When an infinitive modifies a verb, adjective, or another adverb, it functions as an adverb. It often expresses purpose, reason, or result and usually answers the question ‘Why?’

Examples: 

• She studies hard to pass the exam.  (Why does she study hard? To pass the exam)

• He went to the store to buy milk.

• I am happy to help. (To help modifies the adjective happy.)

 

How to Use an Infinitive in a Sentence

Infinitives appear in several different structural patterns. Here are the most important ways to use them correctly.

Continuous Infinitives

A continuous infinitive uses the structure to be + present participle (-ing form). It suggests an action that is ongoing or in progress.

Example: She seems to be enjoying herself.

Split Infinitives

A split infinitive occurs when an adverb or adverbial phrase is placed between to and the base verb. While historically controversial in formal writing, split infinitives are widely accepted in modern English when they aid clarity or emphasis.

Example: You need to carefully read the instructions.

Passive Infinitives

A passive infinitive uses the structure to be + past participle. It is used when the subject receives the action rather than performing it.

Example: She wants to be promoted.

Perfect Infinitives

A perfect infinitive uses to have + past participle. It refers to an action that is completed before the time of the main verb and is often used to talk about hypothetical or regretted situations.

Example: She seems to have forgotten my name.

 

What is an Infinitive Phrase?

An infinitive phrase consists of an infinitive along with its modifiers, complements, or objects. It follow the structure: Infinitive + Additional Words

Examples:

• to finish the assignment

• to win the competition

• to improve communication skills

Examples in sentences: 

• Her goal is to win the competition.

• He wants to improve his English speaking skills.

• We planned to visit the museum during the holidays.
  
  

Infinitives vs Gerunds

Both infinitives and gerunds are non-finite verb forms, which mean they neither shows tense or has a subject. They can both function as nouns. However, they are formed differently and have distinct patterns of use. Gerund is formed by adding -ing to the base verb (running, eating, studying). It always functions as a noun. Where as infinitive is formed with to + base verb (to run, to eat, to study). It functions as a noun, adjective, or adverb.

Infinitives vs Prepositional Phrases

When learning about infinitives, a common confusion is the difference between infinitives and prepositional phrases. As both begin with the word ‘to’, but have entirely different functions.

The main difference is that in infinitives, to is followed by a verb, whereas in a prepositional phrase, it is followed by a noun, pronoun, or noun phrase.

Examples of infinvites: 

• She went to study.

• He wants to help 

Examples of prepositional phrase:

• She went to the library.

• He went to the market.

 

Infinitives Examples

Here are some examples of infinitives used in sentences.

• I want to become a doctor.

• She hopes to win the prize.

• They decided to start a business.

• We need to complete the project.

• He promised to help us.

• The students gathered to discuss the topic.

• I have an assignment to finish.

• She works hard to achieve her goals.

• They plan to visit Chennai next month.

• My dream is to travel around the world.
  
  

Infinitives Exercises

Exercise 1: Identify the Infinitives

Underline the infinitive in each sentence.

1. I want to learn Spanish.

2. She likes to dance.

3. We hope to win the match.

4. He plans to visit Delhi.

5. They decided to stay longer.

Answers:

1. to learn

2. to dance

3. to win

4. to visit

5. to stay

Exercise 2: Fill in the Blanks

Complete the sentences using suitable infinitives.

1. I need _____ my homework.

2. She wants _____ a new language.

3. They hope _____ the competition.

4. We plan _____ tomorrow.

5. He promised _____ on time.

Answers:

1. to finish

2. to learn

3. to win

4. to leave

5. to arrive