The main differences between classical Chinese and modern Chinese were as follows: 1. The difference in language forms: classical Chinese is an ancient written language that uses concise and implicit language to express ideas, while modern Chinese is a modern Chinese language that uses concise and clear language to express ideas. 2. Different ways of expression: classical Chinese pays more attention to details and rhetorical devices. For example, when using classical Chinese to express a meaning, you often need to use metaphor, exaggeration, antithesis and other rhetorical devices. Modern Chinese pays more attention to logic and objectively, using more straightforward, simple and objective language to express ideas. 3. Different language styles: The language styles of classical Chinese and modern Chinese are also different. The classical Chinese is more formal and rigorous, while the modern Chinese is more free and flexible. Both classical Chinese and modern Chinese have their own unique characteristics and advantages. They use different language forms and expressions in different historical periods and different application scenarios, but they are both important tools for human communication and expression.