An infinitive verb, or a non-finite verb, is the basic form of a verb that presents an action as an idea or a concept rather than the specific action of a subject. An infinitive verb often follows the word “to” (as in “to walk”). In the English language, verbs are words that describe or name an action or state of being. English verbs come in a variety of forms and grammatical functions: regular and irregular verbs, auxiliary verbs, linking verbs, passive and active verbs, and so forth. An infinitive phrase is simply a phrase that contains the infinitive form of a verb, a non-finite verb that presents an action as a concept or idea. An infinitive verb can take modifiers, objects, and other complements to form an infinitive phrase. The phrase adds meaning and context to the verb, thus completing the sentence. In some cases, the infinitive phrase can be the subject of a sentence. Consider the following example sentence: “Their frantic efforts to swim only made them tired.” Here, “to swim only made them tired” is an infinitive phrase that modifies and completes the infinitive verb “to swim.” The infinitive form of the verb cannot be conjugated, and unlike finite verbs, infinite verbs function as other parts of speech, like nouns, adjectives, and adverbs. When using the base form of an infinitive verb, it is helpful to remember that these often appear with the modal verbs such as “do,” “be,” “have,” “can,” “could,” “should,” “would,” “shall,” “may,” “might,” and “must.” For example, “I should take more naps.” The base form can also appear when the clause is constructed in the passive voice, such as “Mark my words, they will be caught.” Infinitive verbs with the preceding particle “to” (as in “to fly” and “to speak”) are known as full infinitives. When using infinitive verbs, the “to” is part of the verb and does not act as a preposition or begin a prepositional phrase. Infinitive verbs that appear without the preceding “to” are known as bare infinitives. Although infinitive verbs do not have tense, they can still a grammatical aspect, which describes how a verb exists within time. There are four ways to use simple infinitive verbs with different aspects. 1. __Simple infinitive__: Examples of this type of infinitive include “to catch” (active form) and “to be caught” (passive form). 2. __Perfect infinitive__: Examples include “to have caught” (active) and “to have been caught” (passive). 3. __Continuous infinitive__: Examples include “to be catching” (active) and “to be being caught” (passive). 4. __Perfect continuous infinitive__: Examples include “to have been catching” (active) and “to have been being caught” (passive). Infinitive verbs do not function in sentences like regular verbs, which usually appear in the predicate and describe an action performed by the subject of the noun clause. Instead, they operate as nouns or noun phrases, adjectives, and adverbs. Consider the following sentences: 1. __“To break the record was his sole motivation.”__ In this sentence, the infinitive verb “to break” is a noun and the subject of the sentence. 2. __“If I learn to code, I will have a valuable skill.”__ In this conditional sentence, “to code” is an infinitive verb acting as a specific kind of noun—a direct object. The infinitive verb follows the main verb “learn.” Infinitive verbs can also act as indirect objects. 3. __“I am teaching my students to read Sanskrit.”__ In this case, the infinitive “to read” is an object complement, a kind of noun that gives additional information about the object of the verb. 4. __“Lend her a bike to ride.”__ In this sentence, the infinitive verb “to ride” is an adjective modifying the noun “bike.” If you were to replace “bike” with the adjective clause “that she can ride,” the sentence would still work, indicating that it is acting as an adjective. 5. __“Give me a tablet to practice on.”__ Here, “to practice” is an adjective that modifies the noun “tablet.” 6. __“They returned to complete the task.”__ In this sentence, “to complete'' modifies the verb “returned.” “So they could complete the task” is an adverbial clause, indicating the role of the infinitive as an adverb. 7. __“I walked across the bridge to raise money for charity.__” In this sentence, “to raise” is modifying the verb “walked,” which is the past participle of the verb “walk.” If you replace the infinitive with an adverb phrase and it still works, the infinitive is operating as an adverb. In some examples of infinitives, an adverb separates the verb from the particle “to.” This is known as a split infinitive. For example, “The convict needed time to carefully plan her escape.” “To carefully plan” is a split infinitive. Become a better writer with the [MasterClass Annual Membership](https://www.masterclass.com). Gain access to exclusive video lessons taught by the world’s best, including Malcolm Gladwell, Neil Gaiman, Walter Mosley, Margaret Atwood, Joyce Carol Oates, Dan Brown, and more. An infinitive is a base form of a verb. Learn the different ways infinitive verbs can function in a sentence.