A verb is a word that describes an action, occurrence, or state of being. It is a fundamental part of speech in the English language and helps to convey what the subject of a sentence is doing. For example, in the sentence "The dog barks," the word "barks" is the verb that shows the action performed by the subject, which is the dog. Verbs can be categorized into different types, such as action verbs, linking verbs, and auxiliary verbs. Action verbs express physical or mental actions, like run or think. Linking verbs, such as is or seem, connect the subject to additional information. Auxiliary verbs, like have or will, help to form different tenses and moods.