On the afternoon of May 7, 2021, Mr. Hu Chirui, Professor of Chinese Department of Peking University, Director of Ancient Chinese Teaching and Research Section, and Doctoral Supervisor, gave a lecture entitled "Complex Sentences "Yuqi" of Ancient Chinese and Their Related Marks" to all teachers and students in the lecture hall on the fourth floor of the school library. The lecture was presided over by Professor Gao Yuhua, Associate Dean of School of Chinese Language And Literature.

The lecture took the complex sentences of "Yuqi" in ancient Chinese and their associated marks as samples to illustrate that the complex sentences in Chinese often reflected the speaker's "subjective impression". Professor Hu summarized the complex sentence of "Yuqi" in the existing documents handed down from ancient China and unearthed documents and divided them into three  forms. Meanwhile, he classified the related words as its marks into two categories: "Ning" (expressing willingness) and "Ruo/Ru" (expressing consent), pointing out that both of them revealed the obvious subjectivity of the speaker. Then, Professor Hu traced the origin of the associated marks in the complex sentences of "Yuqi" and questioned the generally accepted view that "Yu" in "Yuqi" was a conjunction. Instead, he pointed out that it was originally a verb expressing permission and approval. Not only did he list a large number of cases in historical documents, but also reinterpreted "Huo", a controversial and difficult word in unearthed documents from the perspectives of phonology and grammatical structure, illustrating that it was more appropriate to interpret it as "Ruo" (expressing promise). After that, the word-forming process of "Yuqi" was combed. Professor Hu made full use of the "left structure" in generative grammar to reveal the nature of "Qi" as an anaphora pronoun, and then analyzed the grammaticalization process and reasons of "Yuqi". Finally, Professor Hu analyzed the reasons for the differences in the classification of complex sentences of "Yuqi". Complex sentences of “Yuqi” have common features in terms of relevance marks with other four kinds of complex sentences, such as transitional complex sentence, hypothesis complex sentence, concessional complex sentence and cause and effect complex sentence. That is, most of marks were developed from verbs with the meaning of consent, willingness and so on. Therefore, they all showed two kinds of the most obvious subjective marks of the speaker, which made it difficult to completely distinguish them.

In the interactive session, Professor Hu answered the questions that teachers and students were all concerned about according to the statistics of the existing corpus, such as the conditions for the formation of words and the time for the formation of complex sentences.

Finally, Professor Gao Yuhua concluded that Professor Hu's lecture seemed to be a small topic but had a large framework", and gave a refreshing reinterpretation and analysis on the common phenomena and viewpoints. Professor Hu made full use of Chinese and foreign linguistic theories and knowledge in both ancient and modern times, to question the conventional viewpoints of the academic community. His detailed and rigorous demonstration, broad academic vision and proficiency in language materials set an academic example for the teachers and students. During the lecture, Professor Hu shared many research topics for further discussion and pointed out the direction of these researches, which benefited the teachers and students a lot.