Infinitive (Non-finite verb)

Infinitive - 

 To + base form of the verb. 

An infinitive is a non-finite verb. It is form with to + base form of the verb & acts as a noun, adjective, or adverb. 

E.g. -  To play, to eat, to write, to give, to take, to jump, to laugh, to go, etc. 

The present infinitive has two forms :

To infinitive  -  to + base form 

Zero infinitive  -  base form

Although infinitives are verbs they do not function as verbs instead they are used as nouns, adjectives or adverbs.

 

 Infinitives as Nouns - 

As we all know noun is a naming word. When an infinitive is used as the subject or direct object in a sentence, it functions as a noun. 

Example - 

• To advise others is easy. 

If we ask the question who or what is so easy? 

We find the answer to advise. 

To advise is an infinitive form of the verb 

(In this example the infinitive to advise is the subject of the sentence and it functions as a noun.) 

 We can also write this sentence in this way. 

It is easy to advise others. 

• He likes to do it. 

( In this sentence the verb is 'like' 

Who or what receives the action of being likes? 

To do

It means to do which is the infinitive form of the verb, is the direct object of the sentence & functions as a noun that expresses an opinion. 

It could be replaced with a person, place, or thing. 

He likes.............. 

• I really need to eat something.  ( Noun) 

Infinitives as adjective - 

As we know an adjective is a word that describes or modifies a noun or a pronoun. It means infinitives function as adjectives when they modify or describe nouns in a sentence. 

Examples -

• He wants a book to read.   (adjective) 

In this example the verb is 'want'. Book is a noun &  to read is an infinitive form which is describing the noun 'book'. 

It means the infinitive 'to read' is used as an adjective. (he don't want only a book, he wants the book to read) 

• He has some letters to write. 

In this example the word 'letters'  is a noun, &  'to write' which is an infinitive form of the verb, is used to describe letters. It means this infinitive is used here as an adjective. 

Infinitives as adverbs - 

 As we have already learnt that adverbs describe or modify adjectives,  verbs or other adverbs. 

It means infinitives function as adverbs when they are used to give more information about adjective, verb or other adverbs in a sentence. 

Usages of Infinitives - 

1) To define the purpose of an action,

2) As the subject of the sentence, 

3) As direct object of the sentence, 

4) As subjective complement, 

5) As an adjective, 

6) As an adverb, 

7) After an adjective, 

8) Used with question word.