"Enduring" refers to the vocabulary system and grammar system of classical Chinese, which was formed on the basis of spoken language before the Han Dynasty. For example, in The Analects of Confucius, "The master wants what he wants, and so does man." There are nine function words in one sentence, which shows that every function word in spoken language at that time was recorded. This kind of spoken language did not exist in Wei, Jin, Southern and Northern Dynasties, Sui and Tang Dynasties, Five Dynasties, Song and Yuan Dynasties and Ming and Qing Dynasties. When writing an article, take the works of the pre-Qin and Han Dynasties as a model and imitate them deliberately. In this way, the language before the Han Dynasty has become a written language that runs through thousands of years of history in China, and this written language is classical Chinese. Of course, because of imitation, the classical Chinese written by the authors of past dynasties can't be exactly the same as the language before the Han Dynasty, which makes the classical Chinese have some subtle changes in the same way. However, this change has not changed the basic characteristics of classical Chinese. Therefore, regardless of the pre-Qin and Han Dynasties, or the classical Chinese works in Song, Yuan, Ming and Qing Dynasties, their basic vocabulary and grammar are basically the same. This gives us convenience objectively: as long as we study classical Chinese, we can freely absorb the needed nutrition from the vast amount of ancient books without the limitation of the times. If ancient books are written not in classical Chinese, but in vernacular Chinese in different periods of history, let us inherit this heritage.
The characteristics of "divorced from spoken language" make classical Chinese difficult to understand. From Wei, Jin, Southern and Northern Dynasties to today, learning classical Chinese is not an easy task. Because the standard of "meeting" is different, the difficulty of learning is also different. The standard of understanding classical Chinese in feudal society is to be able to read and write, while the standard of understanding classical Chinese in modern society is only to be able to read. Relatively speaking, the "meeting" of modern people is not so difficult. In addition, the difficulty of reading is also reduced. Even so, it is still difficult for modern people to learn to read classical Chinese ancient books. With the development of language, the times are too far apart, and we are unfamiliar with the lexical meaning and grammatical features of classical Chinese. We are either unfamiliar with the history, culture, laws and regulations recorded in ancient books, or have never been exposed to them. These are all difficulties in learning classical Chinese. However, if you want to read ancient books, you must learn classical Chinese. Classical Chinese is a stumbling block in front of the treasure house of cultural heritage. If we make up our minds to subdue this tiger, the door of the treasure house will be open to us and we will gain a lot. If we hesitate to touch this tiger, the door of the treasure house will be closed and our losses will be great.