Look at the following sentences:
- To err is human.
- To retreat now would be a disgrace.
What are the subjects of these two sentences? You will have noticed that they are ‘to err’ and ‘to retreat’ – both infinitives. Thus we have seen that the to-infinitive can be used as a noun to form the subject of a sentence.
Although the to-infinitive can be used as the subject of a sentence, it is more common to write these sentences with a preparatory it as the provisional subject.
- It is human to err.
- It would be a disgrace to retreat now.
To-infinitive as the object
Study the following sentences.
- John likes to swim in the sea.
- Alice decided to meet the principal.
- Peter wants to go abroad.
John likes … what? To swim in the sea
Alice decided … what? To meet the principal
Peter wants … what? To go abroad
Here the infinitives to swim, to meet and to go are the objects of the verbs likes, decided and wants respectively. The to-infinitives are thus used as nouns to form the objects of transitive verbs.
To-infinitives as subject complements
Read the following sentences.
- The best thing to do now is to vanish.
- Your duty is to support her.
Here the to-infinitives to do and to support are the complements of the subjects thing and duty.