Does Li Bai write poems in Mandarin or dialect?

Use Chinese. Middle ancient Chinese, to be exact. There are great differences in pronunciation between medieval Chinese and modern Chinese. The pronunciation of its standard language, the so-called Mandarin (of course, the word Mandarin didn't exist at that time), is closer to Cantonese now than to Chinese now. Now Chinese pronunciation actually changed in the late Tang and Five Dynasties. Some voices have disappeared. Now both voiced and unvoiced sounds in Mandarin occurred in that period. Of course, Li Bai's poems were written in the standard language at that time, so we can still understand them now, but if we read them with the pronunciation at that time, we probably won't understand them. But at that time, the quasi-pronunciation of standard language was definitely not Shaanxi dialect, just like Beijing dialect is different from Mandarin now. We can say that Mandarin (called Mandarin in Ming and Qing Dynasties) has a decisive influence on Beijing dialect. Being unable to speak Beijing dialect has a decisive influence on Putonghua. To some extent, the original dialect of Beijing before it became the capital was eliminated by Putonghua. This happens not only in Beijing, but also in other parts of China as the capital, such as Nanjing, which is located in the southern dialect area. However, Nanjing dialect is very different from the dialects in the surrounding areas, but it is close to the northern dialect because it was also the capital of a long time ago. Xi 'an and Luoyang are roughly the same. To sum up, Li Bai used the standard language at that time in his poems, which could not be Shaanxi dialect, let alone Sichuan dialect. Needless to say, in ancient times, even in modern times, was it possible for a person who could not speak Mandarin to roam in a country far from home? Who can read the written article? As for rhyme, since it is not a dialect rhyme, there is no awkward problem. What we are talking about now is the evolution of ancient prose, which has not changed as much as in other countries, but it still has some characteristics. So, on the whole, your feelings will not change. It is more or less awkward to replace it with ancient dialects. .