Simple Examples:
* Hot coffee is the opposite of cold coffee.
* The happy child laughed, but the sad child cried.
* The light was turned on, but the room was still dark.
More Complex Examples:
* Generous donations were made to the charity, in contrast to the selfish actions of the other donors.
* Success in this endeavor requires hard work, while failure is often a consequence of laziness.
* The optimistic outlook of the team helped them through tough times, unlike the pessimistic views of their opponents.
Figurative Examples:
* The rough exterior of the old building hid a smooth and elegant interior.
* Her sharp wit was always a welcome addition to the conversation, but her blunt honesty could sometimes be hurtful.
Remember: Antonyms are words that have opposite meanings. When you use them in a sentence, you highlight the contrast between the two ideas.