English Grammar for the Utterly Confused - Laurie Rozakis 2003

Infinitive Phrases
Chapter 7 Phrases and Clauses
Part 3 Sentence Sense

The infinitive is a form of the verb that comes after the word to and acts as a noun, adjective, or adverb. An infinitive phrase contains modifiers that together act as a single part of speech.

His goal, to get promoted before age 30, didn’t seem realistic.

The infinitive phrase “to get promoted before age 30” modifies the noun goal.

The honorees did not want to attend the banquet in the evening.

The infinitive phrase is “to attend the banquet in the evening.”