Infinitives and Infinitive Phrases

May 22, 2021

Definition: An infinitive is a verb that has not been conjugated (changed to show person or tense). In English, infinitives generally use to with the base (present) form of the verb. The infinitive can work as a noun, an adjective, or an adverb.

Noun: To drive would be my first choice. Mom’s first choice is to fly.
Adjective: Watermelons are good fruits to eat.
Adverb: We used our binoculars to see.

Sometimes the infinitive uses the perfect, progressive, or passive form of the verb.

I want those books to be read. (passive)
By tomorrow, I want those books to have been read. (perfect passive)
By tomorrow, I want you to be reading your books. (progressive)
By Friday I expect you to have started your reports. (perfect)

Definition: An infinitive phrase is made up of the infinitive verb with its object and modifiers.

Noun: To drive to Chicago would be my first choice. Mom’s first choice is to fly to her hometown.
Adjective: Watermelons are good fruits to eat when you are hot.
Adverb: We used our binoculars to see the dolphins in the ocean.

Negative adverbs: Sometimes an infinitive verb will have an adverb like not or never before the verb itself. It is part of the infinitive phrase.

I told your father not to bring your puppy when he came to pick you up.
I warned you never to drive without your driver’s license.

Hint: The word to is also a preposition. If the word to is before a verb, it is part of an infinitive. If the word to is before any other word, it is probably a preposition.

I asked you to bring the book you borrowed. (Bring is a verb; to bring is an infinitive.)
I took my little sister to the movies. (To the movies is a prepositional phrase.)

To split or not to split?Definition: An infinitive with an adverb between the two parts is called a split infinitive. The adverb is often part of the infinitive.

Is it best to not split infinitives?
Is it best not to split infinitives?

Some teachers teach this as a hard and fast rule. They believe it is preferable to keep the two parts of the infinitive together unless the result is awkward. This seems to be another example of overkill of a rule. Sometimes it is better not to split the infinitive. Sometimes splitting it is the best way to write the idea. In formal writing, rewording a sentence to avoid a split infinitive is often the best choice.

I need to quickly stop for some gas before we leave. (could work)
I need to stop quickly for some gas before we leave. (better in formal writing)

Heather likes to before choir warm up her voice. (doesn’t work)
Heather likes to warm up her voice before choir. (better)
Before choir, Heather likes to warm up her voice. (better)