What part of speech indicates the action in a sentence?

The correct answer is a verb because it specifically denotes the action that occurs in a sentence. Verbs express what the subject is doing, whether it be an act like running, thinking, or feeling, and they are essential for creating meaningful and complete sentences. For example, in the sentence "The dog barks," the word "barks" is the verb that illustrates the action of the dog.

In contrast, nouns identify entities—people, places, things, or concepts—but do not indicate action. Adjectives describe or modify nouns and therefore do not convey action either. Pronouns serve as substitutes for nouns to avoid repetition, but they likewise do not express action. Thus, in terms of grammatical function, only verbs signal action within a sentence.