The suffix "ly" is commonly used in the English language to form adverbs from adjectives. When added to an adjective, it typically indicates the manner in which an action is performed. For example, the adjective quick becomes the adverb quickly, describing how something is done. In addition to forming adverbs, "ly" can also appear in some adjectives, such as friendly or lovely. These words describe qualities or characteristics. Overall, "ly" helps to enhance language by providing more detail about actions and attributes.