XU Kai's Contribution to the Theory of Extension of Word Meaning

There are two contributions XU Kai has made to the theory of extension of word meaning: First,based on XU Shen's The Six Categories of Chinese Characters and the relationship between borrowed meaning and original meaning,XU Kai categorized the borrowed words,which helped the Qing linguists to further define the concepts of loan and extension,and to straighten out the relationship between the two.Second,XU Kai the enumerated extended meanings of many words in A Running Commentaries on An Analytical Dictionary of Characters and found ways to extension.XU Kai enlightened many later scholars to go further into extension,finally make it an important theory in word meaning.