1.3 Research significance

Given those unresolved problems in the synchronic investigation on break verbs, our proposed diachronic study is significant in the following four aspects.

First of all, since “diachrony within synchrony equals variation” (Geeraerts 1997: 6), a diachronic semantic study on conceptual variation will display the traces and principles of language and cognitive development. Although it might be uneasy to predict language's future developing trend, a closer look at the evolutionary trajectory of polysemous break verbs affords a key to understanding how the human mind continually adapts and extends its conceptual apparatus (Evans 2010). Moreover, the integration of synchronic and diachronic perspectives refutes Saussure's underestimation of the diachronic perspective. For Saussure, the relations between elements of a language are located in the consciousness of speakers. The psychological unreality of diachronic relations leads Saussure to assign historical phenomena to a totally different domain of investigation (Weinreich et al. 1968: 120). This study demonstrates that a diachronic investigation shows the psychological reality of conscious speakers across different time periods. A comparison of linguistic categories across historical stages reveals the cognitive development of a community on the one hand and indicates social-cultural advancement on the other hand.    

Secondly, Mel'čuk (1981: 51) notes that “Not only every language, but every lexeme of a language, is an entire world in itself”. In this sense, the significance of this diachronic study resides in its revelation of the world of Chinese verbs of separation like pò, qiē, and kāi across different historical stages. On the one hand, the diachronic trajectories of these verbs in their conceptual ranges are dated and visualized in terms of their prototypical conceptual structures. On the other hand, the interaction among these verbs is explored and how their conceptual boundaries vary diachronically is reported. Such diachronic conceptual variation demonstrates that human categorization of their external experience of separation is not invariant but dynamic.

Thirdly, theoretically, a lack of theoretical innovation and theoretical application characterizes the research status quo of diachronic studies, particularly in Chinese (Wu 2015). The empirical employment of DPS in Chinese break verbs introduces an applicable and analytical theoretical framework for future diachronic studies. Specifically speaking, DPS affords a prototype-based analysis of the conceptual structure of lexical items. Lexical items are not simply summarized in terms of their extensional and intensional readings but structurally analyzed in terms of their prototypical and peripheral usages as well as their prototypical and peripheral readings. In addition, DPS offers an interpretive apparatus for explaining diachronic conceptual variation. Two extensional hypotheses and two intensional ones have been put forward to explain and predict conceptual variation. Two characterizing features of prototypical structure evolution, namely structural stability and flexible adaptability, are also brought forth.

Finally, this study brings together diachronic semantics, cognitive linguistics, corpus-based methods as well as empirical methods like MCA and Ctree. In this sense, it is not only significant in providing empirical evidence for diachronic variation but also significant in contributing quantitative methods to the diachronic semantic investigation. It is not expected that this bold attempt will completely change the research status quo of example enumeration in diachronic studies. But it is expected that statistical methods and linguistic evidence will play an increasingly important role in demonstrating language change and predicting language development.