"On and off," "front and back," and "happy and sad" are common examples of antonyms or opposites. Some words have more than one opposite. For example, both "little" and "small" are antonyms of "big," and the opposite of "easy" can be "hard," "difficult" or "challenging." These word sets are generally referred to as graded antonyms because several terms may exist at varying levels between each opposite, such as happy, sad, depressed, grievous and heartbroken, or healthy, sick, ill and diseased.
Complementary antonyms are true opposites with no degrees of variation in between. For example, a light is either on or off, and a person is either dead or alive. "Inside and outside," "day and night," "black and white" and "give and take" are other common pairs of complementary antonyms.
Relational antonyms are types of complementary opposites and are also referred to as converses. These word pairs are complementary opposites, but they also have a relationship with one another and cannot exist apart. For example, there is no parent without a child, and something cannot be borrowed if it is not lent. Other examples of relational antonyms include "north and south," "employer and employee," "offense and defense" and "front and back."