Antimetabole is a rhetorical device that involves repeating a phrase or sentence in reverse order. This technique emphasizes a contrast or highlights a relationship between the two parts of the statement. A well-known example is the phrase, "Ask not what your country can do for you, but what you can do for your country," attributed to John F. Kennedy. This device is often used in speeches and literature to create a memorable impact. By flipping the structure, antimetabole can enhance the meaning and provoke thought, making it a powerful tool in persuasive writing and oratory.