An infinitive is a verb form

can be used as a noun, adjective, or adverb” –English Composition and Grammar Book
In other words….
Infinitives are verbs that can be used as nouns
Example: To smile is to be happy.
**to smile is an infinitive because it acts as the subject of the sentence**
Infinitives are verbs that can be used as adjectives
That is the book to read.
**to read is an infinitive because it uses a verb to modify or describe the object of the sentence**
Infinitives are verbs that can be used as adverbs
He ran to win.
**to win is an infinitive because it modifies or describes a verb**

What is an Infinitive?

let me help.
Help is the infinitive of the sentence because it acts as a verb, and modifies the object of the sentence.
(*why is help an infinitive and not a verb? Let acts as the verb in the sentence, and therefore help is a verb that is acting as a noun, making it the infinitive.)

Infinitives Without The Word “To”

“to” and the verb of an infinitive.
Ex: “To boldly go where no one has gone before.”
- Star Trek

Captain James Tiberius Kirk

Split Infinitives

sentence. Then, write if it is acting as a noun, an adverb, or an adjective. Check your answers on the answer key and discuss your answers with a partner.
To succeed requires determination.
Judaism is the way to go.
Students need to learn.
I’ll help you study.
I am going to see a movie.

Find the Infinitive