鑽研漢語史的學者們大多利用《朱子語類》的口語文獻性質來體察近代語言現象。本研究可說是反其道而行，正視《朱子語類》為「文人語錄」的特質，據此說明其中「為」字被動式居多的原因。「為」字式是一種與當時白話相對的文言成分，常以類似於「行話」的套語形式摻雜在口語記錄裡。其中又以「為A V」最值得留意，其使用率明顯比過去高出許多，表現力也更為豐富，文中指出一些語法特徵論述「為A V」很可能是受到當時主流口語形式「被A V」的類化。「為」字式的沿用還有一個重要因素是記錄者的書寫習慣，文末針對朱熹弟子個人的用語加以觀察，發現有些人的確好用古語形式，充分展現當時儒家語錄「文言化」的特色。

Researchers of the history of the Chinese language tend to rely on collections of colloquial data, such as Zhuziyulei, to examine the modern linguistic phenomena. This study, however, begins from the opposite direction, by treating Zhuziyulei as a collection of written words used by intellectuals at that time. Based on this presumption, this study attempts to elaborate why wei （為） was more frequently used in a passive form. In contrast to other colloquial forms, the wei （為） construction was a relatively classic form at that time and was often used as jargon, according to written records of lectures. Specifically, focusing on the construction of “為A V” is critical, because at that time the construction was more frequently used and more productive than before. This study indicates some grammatical features to support that the construction of “wei （為） A V” was possibly generalized from the popular colloquial construction “bei （被） A V.” In addition, the pervasive use of the wei construction was due to the form preferences of the writer. At the end of this paper, the writing preferences of Zhuxi’s students are discussed. The results reveal that some students preferred using the classic forms. The tendency of using classic Chinese was a feature of collections of Confucian at that time.