Synonyms of Infinitive: 30 Related Terms, Forms, and Alternatives

The word infinitive refers to a basic form of a verb, usually written with to, such as to read, to write, or to learn. There is no perfect synonym for infinitive because it is a specific grammatical term. However, several related terms and verb constructions can help explain, replace, or contrast with infinitives in different contexts.

Quick Answer

The closest terms related to infinitive include base form, bare infinitive, to-infinitive, verb form, non-finite verb, verbal, infinitival phrase, and verb complement. Some constructions, such as gerunds, participles, and -ing forms, can perform similar grammatical jobs but are not technically synonyms for infinitives.

For example:

• I want to learn. → to learn is an infinitive.
• I can learn. → learn is a bare infinitive.
• Learning is useful. → learning is a gerund.
• The learning process is useful. → learning functions as a participial modifier.

Understanding these differences makes it easier to choose the correct grammatical form.

What Does Infinitive Mean?

An infinitive is a form of a verb that does not show tense or agreement by itself.

The most common type is the to-infinitive:

• to walk
• to speak
• to understand
• to improve
• to communicate

The word to is followed by the base form of the verb.

Examples of Infinitives

• She wants to travel.
• We decided to stay.
• He hopes to succeed.
• They need to study.
• I like to read.

An infinitive can perform several different functions in a sentence. It can act as a complement, express purpose, or function as part of a larger phrase.

What Is a Bare Infinitive?

A bare infinitive is an infinitive without to.

For example:

• She can swim.
• Let him go.
• I heard her sing.
• You should wait.

Here, swim, go, sing, and wait are base forms used as infinitives without to.

Modal verbs such as can, could, may, might, must, shall, should, and will are commonly followed by the bare infinitive.

Are There True Synonyms for Infinitive?

Not really.

Unlike ordinary vocabulary words such as happy and joyful, grammatical terms usually describe specific structures. Replacing infinitive with a random word can make a grammar explanation inaccurate.

For this reason, the following list focuses on 30 closely related terms, alternative descriptions, and grammatical constructions. They are useful when studying or explaining infinitives, but they should not all be treated as exact synonyms.

30 Synonyms and Related Terms for Infinitive

1. Base Form

Simple meaning: The basic form of a verb.

Example sentence:
The base form of worked is work.

Best usage/context:
Use this term when discussing the basic dictionary form of a verb or explaining how infinitives are formed.

2. Bare Infinitive

Simple meaning: An infinitive without to.

Example sentence:
She can dance very well.

Best usage/context:
Use bare infinitive when a verb follows a modal or another structure that does not require to.

3. To-Infinitive

Simple meaning: An infinitive that uses to before the verb.

Example sentence:
He wants to leave early.

Best usage/context:
Use this term when you specifically mean forms such as to go, to write, or to learn.

4. Non-Finite Verb

Simple meaning: A verb form that does not independently show tense or subject agreement.

Example sentence:
In She wants to study, to study is a non-finite verb form.

Best usage/context:
Use it in grammar discussions comparing infinitives with participles and gerunds.

5. Verbal

Simple meaning: A verb form that functions in a sentence in a way similar to another part of speech.

Example sentence:
The infinitive is a verbal in To read is enjoyable.

Best usage/context:
Use it in more formal grammar explanations.

6. Infinitival Form

Simple meaning: A grammatical form associated with an infinitive.

Example sentence:
The infinitival form to write appears after the verb want.

Best usage/context:
Useful in academic grammar discussions.

7. Infinitival Phrase

Simple meaning: An infinitive together with the words connected to it.

Example sentence:
To finish the project on time is an infinitival phrase.

Best usage/context:
Use this when talking about a complete phrase rather than the infinitive alone.

8. Verb Form

Simple meaning: A particular grammatical form of a verb.

Example sentence:
To study is one possible verb form.

Best usage/context:
Useful as a broad, beginner-friendly description.

9. Dictionary Form

Simple meaning: The basic form under which a verb is normally listed in a dictionary.

Example sentence:
Run is the dictionary form of ran.

Best usage/context:
Helpful when teaching beginners about base verbs.

10. Lexical Base

Simple meaning: The basic form or stem associated with a word.

Example sentence:
The lexical base of writing is related to the verb write.

Best usage/context:
More appropriate for linguistic or academic explanations.

11. Verb Base

Simple meaning: The basic form of a verb before grammatical endings are added.

Example sentence:
The verb base in to play is play.

Best usage/context:
Useful when explaining verb formation.

12. Base Verb

Simple meaning: The simplest form of a verb.

Example sentence:
The base verb after must is leave.

Best usage/context:
Common in beginner grammar lessons.

13. Non-Tensed Verb

Simple meaning: A verb form that does not itself carry tense.

Example sentence:
To leave is a non-tensed verb form.

Best usage/context:
Useful in formal grammar discussions.

14. Non-Finite Form

Simple meaning: A verb form that does not function as an ordinary finite verb.

Example sentence:
To finish is a non-finite form.

Best usage/context:
Use it when comparing infinitives with finite verbs.

15. Verb Complement

Simple meaning: A word or phrase that completes the meaning of a verb.

Example sentence:
In She decided to stay, to stay is the complement of decided.

Best usage/context:
Useful when explaining how infinitives function after particular verbs.

16. Complementary Infinitive

Simple meaning: An infinitive that completes the meaning of another word.

Example sentence:
They hope to win.

Best usage/context:
Use this when discussing the relationship between an infinitive and the preceding verb.

17. Infinitive Clause

Simple meaning: A clause built around an infinitive.

Example sentence:
To understand the problem requires careful reading.

Best usage/context:
Useful in advanced grammar explanations.

18. Infinitival Clause

Simple meaning: Another grammatical term for a clause containing an infinitive.

Example sentence:
To become successful takes patience and practice.

Best usage/context:
Common in formal linguistic descriptions.

19. Verb Phrase

Simple meaning: A group of words centered around a verb.

Example sentence:
To learn English quickly is a larger verb-related phrase.

Best usage/context:
Useful for discussing the structure surrounding an infinitive, although not every verb phrase is an infinitive.

20. Gerund

Simple meaning: An -ing form that functions as a noun.

Example sentence:
Reading improves vocabulary.

Best usage/context:
Use this as a comparison with infinitives, not as a true synonym.

21. Gerund Phrase

Simple meaning: A gerund together with its related words.

Example sentence:
Reading books every day can improve vocabulary.

Best usage/context:
Useful when comparing noun-like -ing constructions with infinitive phrases.

22. Present Participle

Simple meaning: An -ing verb form commonly used in progressive constructions or as a modifier.

Example sentence:
The running water was cold.

Best usage/context:
Use this when contrasting participles with infinitives.

23. Participial Form

Simple meaning: A verb form used as a participle.

Example sentence:
The broken window needed repair.

Best usage/context:
Useful for discussing other non-finite verb forms.

24. -ing Form

Simple meaning: A verb form ending in -ing.

Example sentence:
Swimming is good exercise.

Best usage/context:
Use it as a broad term when the exact grammatical function of the -ing form is not yet important.

25. Verbal Noun

Simple meaning: A noun formed from or related to a verb.

Example sentence:
The word building can refer to an activity or a structure depending on context.

Best usage/context:
Useful when comparing noun-like verb forms with infinitives.

26. Purpose Phrase

Simple meaning: A phrase explaining why an action happens.

Example sentence:
She went outside to get some fresh air.

Best usage/context:
An infinitive can express purpose, so this description is useful when explaining its function.

27. Purpose Infinitive

Simple meaning: An infinitive used to explain the reason for an action.

Example sentence:
He went to the library to study.

Best usage/context:
Use this specifically for infinitives that answer the question Why?

28. Full Infinitive

Simple meaning: An infinitive containing to.

Example sentence:
She plans to travel next year.

Best usage/context:
Useful when contrasting a full infinitive with a bare infinitive.

29. To-Form

Simple meaning: A form consisting of to plus a base verb.

Example sentence:
The to-form in to read follows the verb want.

Best usage/context:
Helpful as a simple descriptive term in grammar explanations.

30. Infinitival Verb Form

Simple meaning: A verb form used in an infinitival construction.

Example sentence:
In They decided to leave, to leave is an infinitival verb form.

Best usage/context:
Best suited to formal grammar writing and linguistic discussions.

Comparison Table: Infinitive and Related Terms

Term	What it means	Example	Same as infinitive?
Infinitive	Basic non-finite verb form	to read	Yes
To-infinitive	Infinitive with to	to read	Yes
Bare infinitive	Infinitive without to	read	Yes, a specific type
Base form	Basic form of a verb	read	Related, but broader
Non-finite verb	Verb without independent tense	to read	Broader category
Infinitival phrase	Infinitive plus related words	to read books	Not exactly
Gerund	-ing form functioning as a noun	reading	No
Present participle	-ing form used as a participle	reading	No
Verb complement	Element completing a verb’s meaning	to read	No
Purpose infinitive	Infinitive expressing purpose	to learn	A type of infinitive

Infinitive vs. Gerund

One of the most common areas of confusion is the difference between an infinitive and a gerund.

Compare:

• I like to swim.
• I like swimming.

Both sentences can express a preference, but the structures are different.

To swim is an infinitive.

Swimming is a gerund when it functions as a noun-like element.

Some verbs can naturally take either form, while others strongly prefer one construction.

Infinitive vs. Bare Infinitive

Compare these sentences:

• I want to go.
• I can go.

After want, the normal structure is to + base verb.

After the modal verb can, the verb appears without to.

Therefore:

to go = to-infinitive
go after can = bare infinitive

Infinitive vs. Base Form

These terms are closely connected but should not automatically be treated as identical.

The word work is the base form of the verb.

In to work, the base form appears as part of a to-infinitive.

So:

• work = base form
• to work = to-infinitive

This distinction is especially important for English learners.

How to Choose the Right Synonym or Related Term

Since infinitive does not have many exact synonyms, choose the related term according to what you want to explain.

For Beginner Grammar

Use simple terms such as:

• base form
• base verb
• to-infinitive
• bare infinitive
• verb form

These are easier for new English learners to understand.

For Formal Grammar

Use terms such as:

• non-finite verb
• infinitival clause
• infinitival phrase
• infinitival form
• verb complement

These are more precise for advanced grammar explanations.

When Explaining “To + Verb”

The most useful terms are:

• to-infinitive
• full infinitive
• to-form
• infinitival verb form

For example:

She wants to learn.

Here, to learn is a to-infinitive.

When Explaining a Verb Without “To”

Use:

• bare infinitive
• base form
• base verb

For example:

You should study.

Here, study is a bare infinitive after the modal verb should.

When Explaining Purpose

Use purpose infinitive when an infinitive explains why someone performs an action.

For example:

She went to the store to buy milk.

The phrase to buy milk tells us the purpose of going to the store.

When Comparing Different Non-Finite Forms

Use:

• infinitive
• gerund
• present participle
• non-finite verb

These terms make grammatical comparisons clearer.

Common Mistakes With Infinitives

Mistake 1: Adding “to” After a Modal Verb

Incorrect:

She can to swim.

Correct:

She can swim.

Modal verbs normally take the bare infinitive.

Mistake 2: Using the Wrong Verb Form

Incorrect:

He wants going home.

Correct:

He wants to go home.

The verb want normally takes a to-infinitive when followed by another verb.

Mistake 3: Confusing Infinitives With Gerunds

Consider:

To exercise is healthy.

Here, to exercise is an infinitive.

Compare:

Exercising is healthy.

Here, exercising is a gerund.

They can sometimes perform similar grammatical functions, but they are different forms.

Mistake 4: Assuming Every “To” Is Followed by an Infinitive

The word to can also function as a preposition.

Compare:

I want to learn.

Here, to introduces an infinitive.

But:

I look forward to meeting you.

Here, to is a preposition, so it is followed by the -ing form.

Mistake 5: Calling Every Base Form an Infinitive

A base verb can appear in several grammatical structures.

For example:

They work every day.

Here, work is a finite verb.

But:

They can work every day.

Here, work is a bare infinitive after can.

The surrounding grammar determines the function.

Examples of Infinitives in Everyday English

Infinitive as a Complement

I hope to see you soon.

Infinitive Expressing Purpose

She opened the window to get some fresh air.

Infinitive After an Adjective

It is difficult to explain.

Infinitive as a Subject

To learn a language takes time.

Infinitive After a Noun

He has a decision to make.

Bare Infinitive After a Modal

You should try again.

These examples show why understanding the surrounding sentence is more useful than simply memorizing a list of supposed synonyms.

FAQs:

What is the closest synonym for infinitive?

There is no perfect synonym. To-infinitive, bare infinitive, and infinitival form are closely related grammatical terms, while base form and non-finite verb describe related but broader concepts.

Is “base form” the same as “infinitive”?

Not always. The base form is the basic form of a verb, such as go. The to-infinitive is to go. The same base form can also appear as a bare infinitive after certain verbs and modal verbs.

What is another name for a to-infinitive?

To-infinitive, full infinitive, and to-form can all describe the structure to + base verb, although terminology can vary between grammar resources.

What is a bare infinitive?

A bare infinitive is an infinitive without to. For example, go in You can go is a bare infinitive.

Is a gerund a synonym for infinitive?

No. A gerund and an infinitive are different non-finite verb forms. A gerund generally uses the -ing form, while an infinitive commonly uses to + base verb.

What are examples of infinitives?

Common examples include to eat, to sleep, to read, to write, to study, to learn, to speak, to travel, and to understand.

Why are infinitives important in English?

Infinitives are common in everyday English and can follow many verbs, adjectives, and nouns. They can also express purpose and participate in a wide range of sentence structures.

What is the difference between “to go” and “go”?

To go is normally a to-infinitive. Go can be a base form or a bare infinitive depending on its grammatical context. For example, I want to go contains a to-infinitive, while I can go contains a bare infinitive.

Conclusion

The phrase “synonyms of infinitive” can be confusing because infinitive is a specialized grammatical term rather than an ordinary word with many interchangeable synonyms. The most useful related terms are to-infinitive, bare infinitive, base form, non-finite verb, infinitival phrase, infinitival clause, and verb form.

Remember that these terms do not all mean exactly the same thing. A to-infinitive is a specific type of infinitive, a bare infinitive is an infinitive without to, and a base form is the basic form of a verb that can appear in several grammatical structures.

For accurate English writing and teaching, it is better to choose the term that describes the exact grammatical structure rather than treating every related term as a direct synonym.