Infinitives are verbs preceded by the word “to” that function as nouns, adjectives, or adverbs in a sentence. Examples include:
- to walk
- to purchase
- to achieve
- to grind
- to cater
- to destroy
- to read
- to savor
- to delight
An infinitive does not function as a verb. This means you can never add s, es, ed, or ing to the end.
How can an infinitive function as a noun?
- To walk to work is a requirement for her in locating a suitable apartment.
In this sentence, “To walk” functions as the noun because it’s the subject of the sentence.
- She refuses to cater to his every whim.
“To cater” in this sentence functions as the object of “refuses.”
How can an infinitive function as an adjective?
- Whenever Sandra goes to the book store, she always finds a book to purchase.
The infinitive “to purchase” is an adjective that modifies the noun “book.”
How can an infinitive function as an adverb?
- She agreed to travel with the group on holiday.
The infinitive “to travel” tells us what was “agreed,” functioning as an adverb modifying a verb.
When can you split an infinitive?
According to a strict grammarian, never. It’s been written in stone for decades that “thou shalt not” split infinitives.
Incorrect: Robert tries to quickly finish his English paper so he can spend more time gaming.
Correct: Robert tries to finish his English paper quickly so he can spend more time gaming.
That said, sometimes a sentence reads better with a split infinitive, especially in informal writing. Consider the impact of the following sentences:
- To boldly go where no man has gone before. (Thank you, Star Trek.)
It wouldn’t have the same impact if they’d said:
- To go boldly where no man has gone before.
Consider it your literary license to boldly titillate your audience with carefully placed split infinitives. Just not too many, eh?
Interested in other posts from our "What is..." series?
- What is a Cliché? And Why Should You Avoid Them?
- What are the Different Types of Verbs?
- What are Overused Words?
- What is POV? And How Do You Choose the Best POV for Your Story
- What is a Clause?