“之”字结构和“所”字结构是马建忠论述的重点,也是《马氏文通》最精彩的内容之一,引发了后代学者热烈的讨论,相比之下,关于“之所以”结构的讨论要少很多。“之所以”从一个跨层结构变成今天常用的连词经历了词汇化过程,它的语法性质较古代有了非常大的变化。 The structure of the word “” and the structure of the “” character are the main points of Ma Jianzhong’s discourse and one of the most exciting contents of “Ma’s Wen Tong Tong”, which has led to heated discussion among later scholars. In contrast, The reason why “structure of the discussion is much less. ”The reason why " From a cross-layer structure into the common use of today’s converse lexicalization process, its grammatical nature has greatly changed from ancient times.