Can the ancients understand the vernacular? For example, if you say "Have you eaten" to Li Bai, will he not understand? In fact, I just want to ask if the ancient tedious language is a whole.

1. Ancient written language is different from peacetime. The written language is naturally classical Chinese, which is very unified. Speak differently. Everyone speaks local dialect, but it certainly won't be the vernacular now. Even dialects should be concise and highly generalized. Dialects vary from place to place, but there are not so many dialects now. The older the times, the less dialect languages there are.

Because ancient times and today are not only different in language, but also in vocabulary and methods, it should be difficult for people like Li Bai 1000 years ago to understand the current vernacular. But if you write (of course, you have to write traditional Chinese characters), it is difficult for him to guess the general meaning. However, if you want to tell him in the current Mandarin (which was gradually established on the basis of Nanjing Mandarin in the Ming and Qing Dynasties and gradually formed in the 20th century), he probably won't understand. Because the Mandarin used in the Qin and Han Dynasties may belong to the current Minnan language family, and the Mandarin used in the Tang Dynasty belongs to the Cantonese language family (we don't feel very rhyming when reading some Tang poems, but it is much better to read them in Cantonese), so the ancients of Putonghua may not fully understand it now.