A Study on the Differences Between the Modal Verbs "ke" and "keyi" from the Perspectives of Register Grammar and Prosodic Grammar

Abstract

This paper comprehensively investigates the nuanced differences between the Chinese modal verbs "ke" and "keyi" from the dual perspectives of register grammar and prosodic grammar. By systematically examining dictionary definitions, conducting rigorous qualitative and quantitative analyses of exemplary vernacular Chinese corpora, and reviewing theoretical selections from the People's Daily, this research integrates diachronic evolution and grammaticalization theory to reveal several key findings. At the register level, the analysis demonstrates that "ke" predominantly aligns with the Solemn/Classical Register or the Formal Register, whereas "keyi" is firmly situated within the Common Register. Notably, in Modern Chinese, the Formal Register attribute of "ke" has significantly surpassed its historical Solemn/Classical Register attribute. At the prosodic level, the data indicate that "ke" is highly likely to be followed by disyllabic verbs, whereas "keyi" is more frequently followed by monosyllabic verbs. Furthermore, when preceded by adverbs, the proportion of "ke" following monosyllabic adverbs remains relatively high, but this frequency drops sharply when preceded by disyllabic and polysyllabic adverbs. Ultimately, the differences between these two modal verbs are not merely a matter of superficial prosodic matching; rather, they represent the complex result of a synergistic interaction between inherent register attributes and underlying prosodic rules. The study conclusively shows that register grammar and prosodic grammar mutually constrain and condition each other, jointly influencing the grammatical distribution and functional evolution of modal words in contemporary Chinese.