Infinitives are the most basic construction of a verb. When we talk of a verb as a
general concept, we usually use the infinitive form, which is the uninflected base
form of the verb plus the particle to. For instance:
to run
to walk
to read
to be
to learn
to act
Infinitives can be used as nouns, adjectives, or adverbs in a sentence, but they do
not actually function as verbs—they are used to express an action as a concept,
rather than what is being done or performed by the subject of a clause. For
example:
• “I love to run.” (functions as a noun)
• “I wish I had something to do.” (functions as an adjective)
• “I run a lot to stay healthy.” (functions as an adverb)