Speaking well of someone or something can be easily conveyed by using positive adjectives, such as "praise," "commend," or "applaud." On the other hand, there are several antonyms one could use to express a negative sentiment toward someone or something. For example, "criticize," "denounce," "condemn," or "rebuke" could be used to describe the opposite of speaking well of someone or something. By using these antonyms, we can quickly convey our disapproval or disfavor towards an individual or a certain situation. It's crucial to understand the nuances of language and the various ways we can express our thoughts and feelings towards the world around us.