Which type of word would indicate an action performed by the subject?

A verb is the type of word that indicates an action performed by the subject. In English grammar, verbs are essential components of sentences because they express what the subject is doing, which can be an action, occurrence, or state of being. For example, in the sentence "The dog runs," "runs" is the verb that tells us what the dog (the subject) is doing.

In contrast, adjectives describe or modify nouns; they do not convey action. Nouns represent people, places, things, or ideas, serving as the subjects or objects of a sentence but do not indicate actions by themselves. Adverbs, while they often modify verbs and provide additional information about the manner, time, or place of the action, do not themselves indicate actions. Thus, the classification of verbs as action words makes them uniquely responsible for conveying the actions performed by the subject in a sentence.