Abstract

Many linguisticians in the English research field have detailedly illustrated all kinds of usage of English grammars and roles. However, in the modal auxiliary verbs of English, they have also stated their opinions, but deontic modality and epistemic modality have not been completely studied. Especially, how we transfer of deontic function to epistemic function, and the metaphorical extension in the process by the force dynamics between them is an extremely important aspect. The problem aroused my interest to study. In order to study further language continuous development, I begin from expounding the metaphorical extension of the epistemic function from deontic function, and then infer my own opinions as the conclusion of the thesis.

This work is licensed under a Creative Commons Attribution 4.0 License.