Locate the verbs and adjectives in a sentence. A verb "asserts" something that the subject of the sentence is doing, while an adjective is a descriptive term. For example, in the sentence "Maria plants purple flowers," the verb would be "plants" and the adjective would be "purple."
Look for a word with the suffix -ly. Adverbs frequently end with -ly. For example, in the sentence "The boy affectionately hugged the dog," the adverb would be "affectionately" as it is modifying, or describing, the verb "hugged." How did the boy hug the dog? Affectionately. Another example would be "Maria diligently plants purple flowers." "Diligently" would be the adverb in that sentence.
Once an adverb is distinguished, look for another adverb -- adverbs can modify other adverbs. For example, in the sentence "Muffin played the violin quite easily," both "quite" and "easily" are adverbs. How did Muffin play the violin? Easily. How easily? Quite.
Determine if the sentence contains an adverb clause, which is a series of words to provide more information. An adverb clause contains both a subject and verb and will answer questions such as how, when, where, in what way or how often. An example is the sentence "Tommy's cats bolted when they saw the car." When did Tommy's cats bolt? "When they saw the car," which would be the adverb clause.