Infinitive Phrases

An infinitive is a type of verbal. It is the basic form of a verb, usually with-to in front of it. The infinitive is the present-tense form of a verb. Since infinitives are derived from verbs, they do express actions or states of being. We can use different forms of the infinitive to show different times: The miners is thought to have been working at the time of the earthquake.

Infinitives can also be in a passive form: The house needs to be redecorated.

The infinitive phrase consists of an infinitive, its complement, its modifier, and the related words that follow it. 

Infinitive phrases may have their own subjects. The subject of an infinitive phrase is in the object form: Mary helped him to cut the tree.

The infinitive phrase can function as an adjective, adverb, or a noun. When infinitives function as adjectives and adverbs, they are usually found preceding nouns and pronouns in sentences, and when they function as nouns, they are used as subjects, direct objects and objects of prepositions. Infinitives (to + verb) should not be confused with prepositional phrases (to + noun or pronoun). Infinitives may occur as to + one verb, or they may be part of an infinitive phrase.

The book to review cautiously is on the shelf. 
(to review cautiously is the infinitive phrase that is functioning as an adjective).

 I am ready to walk hastily. 
(to walk hastily is the infinitive phrase that is functioning as an adverb).
The teacher came to help the students. 
(to help the students is the infinitive phrase that is functioning as a noun).