The proper use of an adverb is modifying an adjective, verb or adverb. An adverb will also answer the questions when, how, where and to what extent.
Adverbs will commonly end in –ly, but not all adverbs do. Adding the –ly to an adjective will typically change the word into an adverb. For example, an individual can change the adjective in "she runs quick" to "she runs quickly." Good, on the other hand, is an adjective that –ly cannot be added to because "goodly" is not a word. In this situation, the proper adverb an individual should use in place of the word "good" is "well".