There are two main types of infinitives in English:

To-infinitives, also known as full infinitives, are a type of verb form created by adding the word 'to' before the base form of a verb. They are called 'to-infinitives' because they always include the word 'to'. For example:

Infinitives are used to make infinitive clauses or phrases which can function as the subject, adverb, adjective, direct object, object of the preposition, or complement of a clause.

'To-infinitives' can also be categorized according to their part of speech in a sentence:

Nominal infinitives, also known as infinitive phrases, are a type of construction in which an infinitive verb form is used as a noun in a sentence. Nominal infinitives can also be modified with adjectives or adverbs, just like any other noun in the sentence.

Nominal infinitives can fulfill many grammatical functions in a sentence, such as:

Nominal infinitives as subjects can appear at the beginning of a sentence:

As objects, they can appear after the verbs that are catenative (verbs that need another verb as a direct object).

And also they can appear after the prepositions as the objects of that prepositions:

Adjectival infinitives are a type of construction in which an infinitive verb form is used as an adjective to modify a noun or pronoun in a sentence.

They are used to provide additional information about the noun or pronoun they modify. For example:

Adjectival infinitives are often used after linking verbb. As adjectives, they can appear in two_ positions:

A predicative adjectival infinitive follows a linking verb and describes the subject of the sentence. For example:

A postpositive adjectival infinitive comes after the noun it modifies. For example:

Sometimes to-infinitives are used after wh-words to ask for or to give information. Here is the structure:

Adverbial infinitives are a type of construction in which an infinitive verb form is used as an adverb in a sentence. Adverbial infinitives modify the verb in the sentence, providing additional information about the action being performed.

Adverbial infinitives are to-infinitives that function as:

Adverbial infinitives can appear as adjective complements after adjectives in a sentence. They do not necessarily need to immediately follow the adjective; sometimes a prepositional phrase can come before them. The structure is as follows:

Check out the examples for more clarification:

As an adverb, they can appear both at the beginning and at the end of a sentence. For example:

Bare infinitives are a type of verb form that consists of the base form of a verb without the word 'to' before it. They are called 'bare' infinitives because they are not preceded by the word 'to'. Here are a few examples:

Verbs of perception that are followed by a direct object (whether a noun or pronoun) are often used with a bare infinitive as an object complement. The structure of such a clause is as follows:

Here are a few examples:

We use a bare infinitive after 'why' to make a suggestion. Here are a few examples:

The present perfect tense can be formed using infinitives in English. To do so, you can use the to-infinitive form of the verb 'have' followed by the past participle form of the main verb. Here are a few examples:

Both prepositional phrases and infinitive phrases can begin with 'to'. The key difference between these two is that prepositional phrases are nouns, pronouns, or nominal structures governed by the preposition 'to,'; however, infinitive phrases are verbs or verbal structures governed by the particle 'to.' Pay attention to the examples:

Infinitives are categorized into three main groups:

There are two types of infinitives in English: