Modal particles in Chinese (Simplified) grammar are an essential aspect of the language, adding emotion, tone, or emphasis to a sentence. These particles help communicate the speaker’s attitude or mood and often come at the end of a sentence. Common modal particles include 吧 (ba), 啊 (a), 呢 (ne), and 的 (de). Learning to use modal particles correctly is crucial for mastering Chinese (Simplified) grammar and sounding like a native speaker.