What is an infinitive in English grammar? Definition, types, 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.
- Gerunds vs Infinitives – Understand the difference and correct usage.
- Modal Verbs – When to use bare infinitives after modals.
- Verbs – The Action Words – Foundation for verb forms.
- Participles – Distinguish between infinitives and participles.
- 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: Meaning, Types, and Usage in English
1. What is an infinitive in English grammar?
An infinitive is the base form of a verb, usually preceded by 'to' (e.g., to run, to sing). It functions as a noun, adjective, or adverb in a sentence. Key types include the to-infinitive, bare infinitive (without 'to'), negative infinitive, perfect infinitive, and passive infinitive. Understanding infinitives is crucial for English grammar and exams.
2. What are the different types of infinitives?
English grammar features several infinitive types: To-infinitives (e.g., to read), bare infinitives (e.g., read - used after modal verbs), negative infinitives (e.g., not to go), perfect infinitives (e.g., to have gone), continuous infinitives (e.g., to be reading), and passive infinitives (e.g., to be seen). Mastering these variations is key for accurate sentence construction.
3. What is a bare infinitive, and when is it used?
A bare infinitive is the base form of a verb without 'to'. It's used after modal verbs (can, could, will, would, should, may, might, must), verbs of perception (see, hear, feel, watch), and some causative verbs (make, let). For example: "I can run," "I saw him leave." Knowing when to use the bare infinitive improves grammatical accuracy.
4. How do I identify an infinitive in a sentence?
Look for the base form of the verb, typically preceded by 'to'. However, remember the exception of the bare infinitive. Consider its function in the sentence: Does it act as a noun (subject or object), adjective, or adverb? For example, in "To err is human," 'to err' is a noun phrase acting as the subject. Identifying infinitives helps understand sentence structure and meaning.
5. What is the difference between infinitives and gerunds?
Infinitives are the base form of verbs, often with 'to', and function as nouns, adjectives, or adverbs. Gerunds are '-ing' verb forms that always act as nouns. For example: "I like to swim" (infinitive as noun), "Swimming is my hobby" (gerund as noun). Distinguishing between infinitives and gerunds avoids common grammatical errors.
6. What is a split infinitive, and is it acceptable?
A split infinitive occurs when an adverb comes between 'to' and the base verb (e.g., "to boldly go"). While traditionally considered incorrect, split infinitives are often acceptable in modern English, especially when clarity or natural flow improves. The decision depends on context and writing style.
7. What are some examples of sentences using infinitives?
Here are some examples: "I want to eat." (infinitive as object) "He is too short to reach." (infinitive as adjective) "She studied hard to pass the test." (infinitive as adverb). The versatility of infinitives makes them essential for effective sentence construction.
8. Can infinitives be used as subjects of sentences?
Yes, infinitives can function as subjects. For example, "To err is human." In this sentence, 'to err' is the subject of the verb 'is'. This shows the noun-like capacity of infinitives.
9. What is the rule for forming negative infinitives?
To form a negative infinitive, place 'not' before the base verb. For example: "I decided not to go." or "She tried not to cry." This simple rule ensures accurate expression of negation.
10. How are infinitives used after adjectives?
Infinitives frequently follow adjectives to describe the noun they modify. Example: "I am happy to help." Here, 'to help' modifies the adjective 'happy' and describes the subject's state. This usage is common in various sentence structures.
11. What is an example of an infinitive?
A simple example of an infinitive is "to eat." The base form of the verb 'eat' is combined with 'to' to create the infinitive form. This is the most basic form and is crucial to understanding more complex usages.
12. What is the rule of infinitives?
The basic rule is that the infinitive is formed by 'to' + the base form of the verb. However, there are exceptions, particularly with modal verbs where the bare infinitive (without 'to') is used. Understanding these rules is essential to avoiding grammatical errors.
13. Where are infinitives used?
Infinitives are versatile and appear in various grammatical contexts. They function as nouns (subjects, objects), adjectives, and adverbs, following specific verbs, adjectives, nouns or question words. Understanding these diverse uses is important for advanced grammar.
14. How do you use infinitives?
Using infinitives involves recognizing their function in a sentence. They can be subjects, objects of verbs, or modifiers (adjectives and adverbs). Consider context and the overall sentence structure. Practice is essential for fluent and accurate usage.
