* They express opposite meanings. Antonyms are words that have contrasting or opposite meanings. For example, "hot" and "cold" are antonyms.
* They can be graded or absolute. Some antonyms have a spectrum of meaning between them (like "hot" and "cold" – things can be lukewarm, warm, etc.). Others are absolute opposites (like "dead" and "alive").
* They depend on the context. The antonym for a word can change depending on the context. For example, the antonym for "light" could be "dark" (in terms of brightness) or "heavy" (in terms of weight).
* They can be created through prefixes. Many antonyms are formed by adding a prefix like "un-", "in-", "non-", or "dis-" to a word. For example, "happy" and "unhappy."
* They are important for language comprehension. Antonyms help us understand the nuances of language and make distinctions between ideas.
* They can be used for stylistic effect. Antonyms can be used in writing and speech to create contrast, emphasize points, or add interest.
Let me know if you'd like more information about antonyms or have a specific question about them!