The Infinitive in English
An infinitive is the basic form of a verb. It generally appears with the word to: to go, to win, to be, to fly. (A verb of course is a word that shows an action, an occurrence, or a state of being.)
- I want to go home.
- Farley hopes to win the lottery.
- Maya is trying to be a better person.
- Lulu wants to fly to the Moon.
- To travel the world is all she wants.
The infinitive is a versatile verb form that can function as a noun, adjective, or adverb in a sentence.
The bare infinitive
When the basic form of a verb is used without the word to, it is the bare infinitive. The bare infinitive appears after modal verbs (can, should, must, etc.), verbs of perception (see, hear, watch), and certain other verbs such as let, help, and make.
- You can call them tomorrow.
- I should go.
- You must breathe.
- I saw her press the button.
- Did you hear someone knock?
- I watched it disappear.
- Let it go.
- Can you help me pack?
- Please make me understand what’s going on.
When the basic form of the verb appears with the word to, it is called the to-infinitive or the full infinitive. Without the word to, it is the bare infinitive, also called the zero infinitive.
Forms of the infinitive
The infinitive does not carry tense. It stays in its basic form across the present and past tenses.
- I want to fly to the mountains.
present tense
- I wanted to
flew/fly to the mountains.past tense
As you can see, the main verb want changes from present to past tense (want → wanted), instead of the infinitive to fly, which stays in the basic form.
Although the infinitive does not show tense, it can show aspect: it can still indicate a temporal relationship with the main verb.
- I am glad to fly tomorrow.
Simple infinitive, concurrent with the main verb (am), i.e., the present
- I am glad to be flying today.
Progressive infinitive, shows that the action is in progress
- I am glad to have flown with you today.
Perfect infinitive, indicating a past time
- I am glad to have been flying with you all these years.
Perfect progressive infinitive, duration in the past
The infinitive does not change its form with a change in person. This means that regardless of whether the subject of the sentence is singular or plural, or in the first, second, or third person, the infinitive stays the same.
- You want to fly to the mountains.
- She wants to fly to the mountains.
- They want to fly to the mountains.
Again, the main verb want changes form (want/wants), but the infinitive to fly does not.
Infinitive as subject
Just like a noun, an infinitive can be the subject of a sentence. (The subject is whom or what the sentence is about.)
- To rest is all she wants to do after a long day at work.
- To dance is to live.
- To play as a team is necessary for us to win this match. (infinitive phrase)
- To know him is to love him.
A gerund (verb + ing form) can also be the subject of a sentence. But using an infinitive instead of a gerund makes the sentence more formal, literary, even slightly solemn.
- More formal: To err is human; to forgive, divine.
Less formal: Erring is human; forgiving, divine.
Infinitive as object
The infinitive is often used as the object of a verb.
- Farley agreed to lend them some money.
The infinitive to lend is the object of the verb agreed.
- Lulu loves to meet new people.
- Rita intends to investigate what happened.
Infinitives are commonly used with verbs expressing thought or feeling.
- Nesbit wants to adopt a cat.
- Maya hopes to travel the world.
- Poco likes to drink his coffee cold.
- Farley forgot to lock the door as usual.
Some of these verbs can also be followed by gerunds.
- Poco likes drinking/to drink his coffee cold.
But many verbs can take only infinitives.
- Farley wants
adopting/to adopt a cat.
For more examples, see this article on when to use infinitives versus gerunds.
Infinitive as adjective
An infinitive can provide additional information about a noun, thus acting as an adjective.
- Tumkin found us a movie to watch tonight.
The infinitive to watch modifies the noun movie.
- Farley needs a car to drive to work every day.
- Maya bought herself a book to read on the flight to Vietnam.
Infinitive as subject complement
An infinitive can be used to describe the subject of a sentence, thus functioning as a subject complement. It then appears after forms of the be verb (is, are, was, were).
- Maya’s dream is to travel the world.
The infinitive phrase (“to travel the world”) describes the subject (“Maya’s dream”).
- Poco’s job was to manage the project.
- Rita’s favorite activity is to ride her motorcycle.
Infinitive as adverb
An infinitive can provide additional information not only about a noun but also about an adjective or a verb. It can therefore act as an adverb.
- I am happy to discuss this with you.
describes why I am happy
- Farley is reluctant to travel abroad.
- Tumkin practices daily to improve his French.
explains why Tumkin practices
- We will negotiate this deal further to reach an agreement.
The split infinitive
When you split an infinitive, you insert a word between to and the verb of a to-infinitive (or full infinitive).
- Rita hopes to someday climb Mt. Everest.
- Farley plans to quickly finish packing and go to bed.
- I need to completely forget this ever happened.
Purists sometimes object to splitting the infinitive on stylistic grounds. Since it cannot be split in Latin, they believe it should not be split in English either. However, it’s perfectly fine to split the infinitive in English to improve clarity or emphasize an adverb.
- I want to not make a mistake.
- I want to clearly understand what’s going on.
For more examples and discussion, see this article on split infinitives.