Cognitive Studies On English Modal Verbs

Among the English modal system, there are a variety of modalizers that are used to express different modal meanings. Within the category of modalizers, there are prototypical modal expressions, e.g. modal verbs; there are also peripheral members, like modal verb phrases, adverbs, adjectives, so on and so forth. The meanings of modality and modalizers are intrinsically gradient, and the properties of gradiance reflect the degrees of factuality that they describe both the subjective and objective world. The properties of discreteness and continuity exist in different events and phenomenon; it is these events and phenomenon that established the subjective and objective world in which we live. So, the objective world is a combination of various events and phenomenon of continuity and discreteness. In this combination, among different individuals, there are continuity and discreteness. This thesis starts from the above point of view, firstly, creates a schema for modalizers of English modal system, secondly, this thesis lays emphasis on the study of modal verbs in the modalizer schema. The study of modal verbs are the concerning point of this thesis.In traditional linguistic works, the studies of modality limit themselves to the simple classifications deontic modality, dynamic modality and epistemic modality. It is clear that the traditional study ignored studying the continuity of modality. From cognitive points of view, based on the theories of categorization and decategorization and polysemy, this thesis focuses its attention to the subjectivity of modal verbs and the analysis on the semantic gradience of modal verbs. Then, from the degree of certainty expressed by modal verbs, we studied the continuity of modal verbs, and established the deontic modal verbs gradience and dynamic modal verb gradience. Then we interpreted the gradience of epistemic modal verbs from the aspect of metaphorical projection.The structure of this thesis is as followed:Chapter one briefly introduced the studies on modality of the linguistic scholars from home and abroad; and then discussed the implications for this thesis.Chapter two is the theoretical base of this thesis. In this part, we have primarily discussed the theories of categorization and decategorization. Chapter three is the core of this thesis. Firstly, we talked about the semantic features of modal verbs. Secondly, based on categorization and decategorization, we constructued a schema of the continuity of modalizers, and this schema succinctly depicted the central members and peripheral members within the category of modalizers. Thirdly, we analyzed the prototypical modal meanings and the peripheral modal meanings of the modal verbs. At last, according to the semantic degree of modal verbs, we established gradience of deontic modal verbs and that of dynamic modal verbs; meanwhile, we also tried to analyzed the motivation that lies behind the already existed gradience of epistemic modal verbs.Chapter four gives proper suggestions and solutions for the drawbacks of modal verbs in current English teaching and learning, and set reference for precisely perceiving the meanings of modal verbs in contexts for English learning.Chapter five is the conclusion for the whole thesis.