What is an Infinitive?

An Infinitive is a verb form that connects to and the base form of the verb.

Generally, infinitives are not affected by tenseOpens in new window, numberOpens in new window or personOpens in new window. They can be used as adjectivesOpens in new window or adjectival phrasesOpens in new window. The infinitive can also be used as an adverbOpens in new window or a nounOpens in new window.

The symbolic sign of an infinitive is the infinitive marker to  +  base form (root) of verb. For example, “to fly,” to spend,” “to measure,” “to quantify,” or “to report,” etc.

A present infinitive describes a present condition i.e., I like to sleep. The perfect infinitive describes a time earlier than that of the verb: I would like to have completed the project.

The infinitive is often used without to after certain auxiliary verbs:

  • You must try.
  • They may return.

It is also used with to after certain adjectives:

  • It is hard to understand him.
  • She’s quick to argue.

It can also be used after nouns:

  • This is a chance to succeed.
  • The time to move is now.
Forms of Infinitives
    Infinitives generally come in two forms:
  • The to-infinitive = to + base form of verb (to sleep)
  • The zero or bare infinitive = base form of verb (sleep)

How to Recognize an Infinitive.

Generally, all infinitives begin with the infinitive marker to followed by the base form (or as also called, the root form) i.e. the basic dictionary form of a verb.

Formular for Infinitives.
To + verb = Infinitive, as in: “to go,” “to play,”, “to account,” “to accommodate,” “to ask,” “to report,” “to panic,” “to win,” — there are so much more. Invariably all the verbs in the English language plus to will form infinitives.

Functions of Infinitives

Infinitives can take the job of adjectiveOpens in new window, nounOpens in new window, adverbOpens in new window, subject complementOpens in new window, etc. in a sentence.

1.  Adjective modifying a noun — In the examples below “to aid,” and “to eat,” functions as adjective modifying the nouns ‘laptop’, and ‘lunch’ respectively.

  • Andy installed a computer program in his laptop to aid his project.
  • The boys visit McDonald’s to eat lunch.

2.  Adverb modifying a verb — The infinitives in the example below modifies the verbs ‘want’ and ‘work’ to make a desired meaning expressing the reason for doing the action of the verbs.

  • I love my wife so much, I want to buy her a gift.
  • Everyone work to earn a living.

3.  Infinitives as subject of a sentence — This usually occur in the beginning of a sentence.

  • To succeed requires discipline, dedication, and hard work.
  • To sleep in the office is unthinkable.

4.  Infinitives as subject complement — Infinitives can function to complement a subject in a sentence, as in:

  • His favorite leisure is to play with the kids.
  • Andy’s only motivation is to succeed in life.

5.  Infinitives as object of a sentence — Infinitives also serve as object of a sentence as in:

  • She can’t afford to quarrel again.
  • You can as well go to sleep.

6.  Infinitives as adjective complement — Infinitives may also serve as adjective complement as in:

  • Andy seems reluctant to say his mind.
  • I will always be quick to tell her my feelings.