Antonyms can be found in a thesaurus entry for a word, usually after the synonyms, which are the opposite of antonyms. Antonyms can also be found at the end of a dictionary entry of a word. These materials provide definitions, parts of speech, synonyms and antonyms for words.
Antonyms can be made by adding certain prefixes to a word. For example, "un" can be added to "likely" to get its antonym: "unlikely." Other prefixes that can be used to make antonyms include "non" and "in." One type of antonym is the graded antonym, which conveys the level of intensity of a word, such as happy, content, sad or depressed.