Infinitive in English

Infinitive in EnglishInfinitive as a basic verbal. Infinitive types, functions and usage.

Infinitive is a basic verbal after semi-notional/helping verbs. It’s the Present Simple verb stem as a noun/adjective/adverb.

Infinitive types

2 infinitive types:

  • bare infinitive as a pure verb stem

I must go.

  • full infinitive (to-infinitive) after the particle to.

to run



Bare infinitives go after

They may arrive soon.

  • the auxiliaries do/did

Did you pass the exam?

  • let’s

Let’s go out tonight.

  • make + (pro)noun object

He made me come here.

  • would rather

I’d rather not stay out late tonight.

  • Why not…?

Why not phone me tomorrow?

  • – perception verbs (forget, learn, teach, train, choose, expect, hope, need, offer, want, would like, agree, encourage, pretend, promise, allow, can(‘t) afford, decide, manage, mean, refuse)

I didn’t hear you come in.

  • help (sometimes)

Can you help me (to) open this?


6 infinitive forms:

  • simple infinitive

to write

  • continuous infinitive

to be writing

  • perfect infinitive

to have written

  • perfect continuous infinitive

to have been writing

  • passive infinitive

to be written

  • passive perfect infinitive

to have been written

Infinitive phrases

An infinitive phrase is infinitive + complements/modifiers (objects).

He helped write the plan. [nominal modifier]

She was looking for a way to earn money. [adjectival modifier]

He shouted to get our attention. [adverbial modifier]

Infinitives are often used in anticipatory it phrases like it’s necessary/important/easy + infinitive.

It’s useless to ask him about it.


Infinitives are used after

  • be

My 1st thought was to phone you.


  • be + adjective + of + (pro)noun

It’s kind of you to help me.


  • the first/second/last/only/best (and other superlative adjectives) + noun/one

He was the only one to die.

  • feeling adjectives (disappointed, glad, happy, pleased, relieved, sad, surprised)

I was happy to meet them.

  • too + adjective

The water was too cold to swim in.

  • adjective + enough

She is rich enough to buy two.


  • complex constructions (complex subjects, complex objects)

I know him to be an honest man.


  • verb + inverted question word

I don’t know what to do.




Infinitives may act as:

  • subjects

To do this is practically impossible.

  • predicatives

Their task was to reach the city before dark.

  • compound verbal predicates

He began to do it immediately.

  • objects

I didn’t mean to disturb you.

  • attributes

He isn’t a man to trifle with.

  • adverbial modifiers

He came to support us.