Identify the verb in the sentence: "The dog barked loudly."

In the sentence "The dog barked loudly," the verb is "barked." A verb is a word that expresses an action, occurrence, or state of being. In this case, "barked" is an action verb that describes what the dog is doing. It clearly conveys the activity performed by the subject, which is "the dog." The other words in the sentence serve different grammatical functions: "dog" is a noun that acts as the subject of the sentence, "loudly" is an adverb that modifies the verb by describing how the dog barked, and "the" is an article that modifies the noun "dog." Thus, "barked" is correctly identified as the verb due to its function as the word that conveys the action within the sentence.