What is an INFINITIVE and a SPLIT INFINITIVE?

An INFINITIVE is a TYPE OF VERBAL.

A VERBAL is a VERB acting like another PART OF SPEECH.

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An INFINTIVE is a VERB posing as a NOUN, ADJECTIVE, OR ADVERB.

An INFINITIVE is a simple verb form proceeded by the preposition “to”

to think – to read – to cut – to swim

However, it is a little trickier to figure out the function of that INFINITIVE

INFINITIVE (VERB acting as a NOUN as a SUBJECT, DIRECT OBJECT, or SUBJECT COMPLEMENT)

To climb Mount Everest was my greatest ambition. (Subject of the sentence)

I attempted to climb Mount Everest. (Direct Object of the sentence)

My greatest ambition is to climb Mount Everest. (Subject Complement of the sentence)

INFINITIVE (VERB acting as an ADJECTIVE)

Wherever she goes, she brings a book to read. (to read modifies the noun – book)

I have a paper to write. (to write modifies the noun – paper)

INFINITIVE (VERB acting as an ADVERB)

Susie ran across the muddy field to bring the boy his lost homework. (to bring modifies the verb – ran. It explains WHY? Susie ran across the field)

Then, what is a SPLIT INFINITIVE?

A Split Infinitive is when you split up the Infinitive with an ADVERB.

To go = Infinitive

To boldly go = Split Infinitive

To read = Infinitive

To quickly read = Split Infinitive