Cognitve Study On The Category Of English Tenses

The tense category of English verb plays an essential role in English language, and it is also one of the core tasks in English teaching and learning. This thesis studies the polysemization of the English tenses with the past tense and present tense as examples by applying the Prototype Theory and Conceptual Metaphor Theory under the guidance of cognitive linguistics, with a focus on the polysemy relationship of the English past tense and present tense, cognitive mechanisms and cognitive motivation of the polysemization of the English tenses, and its implication in English teaching and learning. Tense category of English verb is one of the oldest and most controversial subjects in the history of language studies. Tense is described and defined differently at different periods of time because of English grammarians'various understanding on the concept of tense. Focusing their description of tense uses on the time relation between the actual speech time and event time, traditional grammarians including the expansionists and the reductionists essentially describe English tense from the objectivistic aspect, which lead to the contradiction between tense definition and tense uses. The latter studies, especially the studies of Langacker and Taylor, show us the efficiency of cognitive linguistics on analyzing linguistic phenomena by taking the subjective factors, such as the people's cognition into consideration, and provide a more coherent and systematic explanation of the English tenses. But these studies are just a beginning and this thesis makes a step further to explore systematically the polysemization of the English past tense and present tense on the basis of the former studies.This thesis holds that the English past and present tense are polysemous prototype categories, and they exhibit family resemblance structures and degrees of category membership. For example, the past tense takes the sense of distance in time as its prototypical use, which is more prominent, more accessible, and less effort-costing, and the senses of distance in reality and distance in psychology as its non-prototypical uses. Metaphor is the main cognitive mechanism involved in the polysemization of the English tenses. The prototypical uses of the past tense and the present tense extend to their respective non-prototypical uses through metaphorical mapping on the respective mental basis of the distance image schema and the proximity image schema. In such a way, the "abnormal" uses of English tenses are admitted to the systematic framework of the past tense and that of the present tense respectively. The thesis analyzes the cognitive motivation of the polysemization in the English tenses from the aspect of cognition, function and shift of cognitive domain. Cognitively, polysemization of the English tenses is economically motivated because it makes one single grammatical form include several meanings, and it is iconically motivated because all the senses of the past tense and that of the present tense are semantically related. Functionally, polysemization of the English tenses is motivated by meeting the expression needs of human beings both in content and manner. And from the aspect of the shift of cognitive domains, polysemization of the English tenses results from the appearance of the past tense or present tense in a new cognitive domain, where the source sense(s) would not make sense. This thesis plays a significant role in English tense teaching and learning. If appropriately applied, the research result of this thesis would promote the comprehension, acquisition, and production of English tenses for the Chinese learners.This thesis provides a unified, coherent and systematic explanation for the polysemization of the English tenses. In consequence, the thesis provides a new idea for tense study and broadens the research scope of the Prototype Theory and the Conceptual Metaphor Theory, and it is also enlightening to the teaching and learning of the English tenses.