Uses of the Infinitive

The infinitive is the most basic form of a verb – for example, ‘to run’ or ‘to eat’. Most of the time, we use a verb in a variety of other forms, but sometimes we can also use it in this basic form. Here are some of the main uses of the infinitive:

Infinitive as a noun

Sometimes, the infinitive form of a verb is used not as a normal verb – but as a noun. As a noun, it can be the subject or object of the verb.

• To err is human. (the infinitive ‘to err’ is the subject of the verb ‘is’)
• She likes to run. (the infinitive ‘to play’ serves as the object of the verb ‘likes’)

Infinitive to qualify an adjective or a noun

We can also use the infinitive form after some adjectives and nouns, to give an explanation for the particular adjective or noun. Some of the adjectives are: ‘eager’, ‘happy’, ‘surprised’, etc. The infinitive here helps to give an opinion or explanation to the word.

• She was happy to see him come home. (the infinitive ‘to see’ gives an explanation about why she was happy)
• This is not the time to play. (the infinitive ‘to play’ gives an opinion of the time that is not suitable for playing)

Infinitive as a complement of a verb

The infinitive can also be the complement of a verb.

• Her greatest pleasure is to sing. (the infinitive ‘to sing’ is the complement of the verb ‘is’.)

Infinitive to show purpose

We can also use infinitives to say why we do something (thus, we use ‘to’ in place of a common phrase ‘in order to’ or the phrases like ‘because I (she, he, we or they) wanted to do something).

• Why do people go to Paris?
  … because they want to see the Eiffel Tower.
• …to see the Eiffel Tower.

• I went to the library…
  … because I wanted to get a book.
• … to get a book.

Check out this video on 5 ways to use the infinitive:

Verb Patterns

When used after verbs, infinitives and gerunds can replace a noun as the object of a verb. Whether we use a gerund or an infinitive depends on the main verb in the sentence.

a) verb + -ing

After some verbs, we use verb-ing:

• I enjoy going to the cinema.
• NOT: I enjoy to go to the cinema.

• It was late when we finished watching the movie.
• NOT: It was late when we finished to watch the movie.

Some other verbs which follow this pattern are:

suggest	like	love	stop
finish	keep	avoid	hate
	mind	enjoy

• I hate listening to rap music.
• It didn’t stop raining all day.

b) to + infinitive

After other verbs, we use to + infinitive:

• We wanted to relax on holiday.
• NOT: We wanted relaxing on holiday.

• We decided to go to Greece.
• NOT: We decided going to Greece.

Some other verbs which follow this pattern are:

choose	forget	help	decide
hope	need	plan	want
promise	try	would like	learn

• We hope to go there again next year.
• I promised to buy a present for my sister.

In the negative, we use ‘not to…’:

• We tried not to drink too much ouzo.

Read more about using gerunds and infinitives in this article:

Verb patterns: Gerund vs Infinitive

See also:

Verbs: the Infinitive