What Are Infinitives Definition Types Rules and Examples
An infinitive in English grammar is the basic form of a verb, often used with "to" (like "to eat," "to run"). Infinitives are important for students and competitive exam preparation. Knowing infinitive types, usage patterns, and common rules helps improve writing, speaking, and understanding sentences in daily English.
| Type of Infinitive | Structure | Example | Usage |
|---|---|---|---|
| To-infinitive | to + base verb | to read | After certain verbs, adjectives, nouns |
| Bare infinitive (Zero) | base verb | go | After modal verbs and some others |
| Negative infinitive | not + to + base verb | not to sleep | To express negatives |
| Perfect infinitive | to have + past participle | to have eaten | Actions before another action |
| Passive infinitive | to be + past participle | to be seen | Focus on receiver of action |
What is an Infinitive in English Grammar?
An infinitive in English grammar is the basic, dictionary form of a verb. Most often, it is introduced by "to." For example, "to play" or "to study." Infinitives are non-finite verbs and do not show tense or person.
Types of Infinitives
- To-infinitive: to + base verb (to learn)
- Bare infinitive (zero): base verb alone (help do)
- Negative infinitive: not + to + base verb (not to eat)
- Perfect infinitive: to have + past participle (to have finished)
- Passive infinitive: to be + past participle (to be given)
Infinitive Formation and Rules
How to Form Infinitives
To make a regular infinitive, use "to" with the base verb. For negatives, add "not" before "to" (not to go). Use the bare infinitive after modal verbs and verbs like "let," "make," "see," "hear," and "help."
Infinitive Rules
- Most verbs use the to-infinitive: I want to win.
- Some verbs use the bare infinitive after them: She can swim.
- Use "not to" for negative: He told me not to worry.
- The perfect infinitive shows earlier action: She seems to have left.
- The passive infinitive focuses on action received: The report is to be finished.
Infinitive Examples in Sentences
| Type | Sentence Example | Notes |
|---|---|---|
| To-infinitive | I hope to pass the test. | After "hope," "to" plus verb. |
| Bare infinitive | She must leave now. | After modal verb, no "to". |
| Negative infinitive | He decided not to go. | "Not" before "to". |
| Perfect infinitive | She seems to have forgotten. | Action before "seems". |
| Passive infinitive | The work is to be done tomorrow. | Focus on receiver. |
Where Are Infinitives Used?
- After some verbs: want to eat, agree to help
- After adjectives: easy to understand, glad to see you
- After nouns/pronouns: time to study, something to drink
- After question words: I don't know what to do
- After certain phrases: too hot to eat, enough money to buy
- After modal verbs: can go, should work (bare infinitive)
Common Confusions: Infinitives, Gerunds, and Participles
| Form | Structure | Function Example |
|---|---|---|
| Infinitive | to + verb | He loves to read. |
| Gerund | verb + ing | He loves reading. |
| Participle | verb + ing/ed/en | The broken chair was fixed. |
Infinitives act as nouns, adjectives, or adverbs. Gerunds always act as nouns. Participles act as adjectives or verb parts.
Infinitives in Daily Life and Exams
Infinitives appear in essays, emails, conversations, and exam questions. Knowing how to spot and use them can improve writing and speaking skills and help score better in school and competitive exams. Vedantu offers more English grammar resources for practice and understanding.
- Non-finite Verbs – How infinitives relate to other non-finite verbs.
- Modal Verbs – When to use bare infinitives after modals.
- Verbs – The Action Words – Foundation for verb forms.
- Prepositions of Purpose – Compare infinitives with prepositional phrases.
- Direct and Indirect Speech – Many reporting verbs use infinitives.
- Auxiliary and Modal Verbs – How auxiliary verbs interact with infinitives.
- English Grammar Overview – Broad grammar context.
Infinitives in English grammar are an essential part of writing, speaking, and understanding sentences. Learning their types—like to-infinitives, bare infinitives, and more—along with rules and examples, helps students for exams and daily life communication. Explore more at Vedantu for complete grammar support.
FAQs on Infinitives in English Grammar
1. What is an infinitive in English grammar?
An infinitive is the base form of a verb usually preceded by "to", such as to eat, to go, or to study.
- Structure: to + base verb
- It does not show tense, person, or number.
- Example: She wants to learn English.
2. What are the types of infinitives in English?
The main types of infinitives are the full infinitive and the bare infinitive.
- Full infinitive: to + base verb (e.g., to read)
- Bare infinitive: base verb without “to” (e.g., read after modal verbs)
3. How do you use an infinitive in a sentence?
An infinitive can function as a noun, adjective, or adverb in a sentence.
- As a noun: To travel is my dream.
- As an adjective: I have a book to read.
- As an adverb: She studies hard to pass.
4. What is the difference between a gerund and an infinitive?
The main difference is that a gerund ends in -ing and functions as a noun, while an infinitive uses to + base verb.
- Gerund: Swimming is fun.
- Infinitive: I like to swim.
5. When do you use the bare infinitive?
The bare infinitive is used without “to,” mainly after modal verbs and certain expressions.
- After modal verbs: can, must, should (She can drive.)
- After verbs like make and let: They made him apologize.
- After verbs of perception: I saw her leave.
6. What is a split infinitive?
A split infinitive occurs when a word, usually an adverb, comes between “to” and the base verb.
- Example: She decided to quickly finish her work.
7. Can an infinitive be the subject of a sentence?
Yes, an infinitive phrase can function as the subject of a sentence.
- Example: To exercise regularly is important.
- It can also be rewritten with “it”: It is important to exercise regularly.
8. What is an infinitive phrase?
An infinitive phrase consists of an infinitive plus its objects or modifiers.
- Structure: to + verb + complement/modifier
- Example: She wants to buy a new car.
9. Which verbs are followed by an infinitive?
Certain verbs are commonly followed by an infinitive rather than a gerund.
- Common verbs: want, decide, hope, plan, promise, agree
- Example: They decided to leave early.
10. Why are infinitives important in English grammar?
Infinitives are important because they add purpose, intention, and clarity to English sentences.
- They express purpose: She called to ask a question.
- They show intention or plan: I plan to study.
- They expand sentence variety in writing and speaking.
