"Really" is an adverb used to emphasize the truth or sincerity of a statement. It can express surprise, disbelief, or intensity, often enhancing the meaning of the words it accompanies. For example, saying "I really like this book" indicates a stronger preference than simply saying "I like this book." In conversation, "really" can also serve as a prompt for further explanation or clarification. When someone responds with "Really?" it often signals curiosity or a request for more information. This usage helps to engage listeners and encourages deeper dialogue about the topic at hand, such as a movie, event, or experience.