| The word "text" is used in linguistics to refer to any passage, spoken or written, of whatever length, that does form a unified whole. A text has texture, which is provided by the cohesive relations, and this is what distinguishes it from something that is not a text (Halliday and Hasan 1976: 2). Therefore, "cohesion" is one of the most basic concepts and also an important topic to study in text analysis. It is widely accepted that the publication of Cohesion in English written by Halliday and Hasan in 1976 symbolizes the foundation of cohesion theory. Since then, it has received a lot of attention in the academic circles, because it contributed a lot to text analysis, translation theory, man-machine conversation and also stylistics.Although scholars both at home and abroad have become interested in textual cohesion since the 1960's, and a lot of researches on this topic have been done, most of them concentrated on a few obvious lexical and grammatical cohesive devices of the surface structure. Zhang Delu (1999), when commenting on Halliday and Hasan's cohesion theory, pointed out that there were some other cohesive devices that had been ignored, such as phonetic pattern, intonation, tense and voice, transitivity, etc.Many scholars, from Aristotle till now, have discussed the definitions and systems of "time", "tense" and "aspect", but no agreement has been reached. Most linguists agree that English has two tenses and two aspects. Although there is no future tense in English, it does have many means of expressing future time. Tenses and aspects can be used respectively and can also be combined to form complex aspects. Both tense and aspect systems allow speakers to relate situations to time. But the traditional studies on tenses and aspects were largely limited within sentences, and have rarely been extended to the textual level. Canthey also be used in text analysis, serving as a cohesive device? Many linguists both at home and abroad hold the unanimous view that tense and aspect systems can be used as a cohesive device, which can help to create a coherent text.Only by the late 1970's did the cohesive function of tenses and aspects attract linguists' attention. Yet only a few scholars have touched upon this topic till now and these studies mainly concern free direct speech and free indirect speech in novels. The cohesive functions of tenses and aspects in other kinds of texts have rarely been discussed.This thesis will analyze the cohesive function of different tenses and aspects in different kinds of texts (expository texts, descriptive texts, argumentative texts and narrative texts), so as to further the study on the cohesive function of tenses and aspects. This study is significant in that theoretically it will make a complement to the cohesion theory and practically it can throw light on reading and writing teaching.Besides introduction and conclusion, this thesis consists of five chapters.Introduction mainly introduces the purpose of this study. At the same time, the research methodology and also methods of collecting data are provided.Chapter One is the literature review of studies on cohesion, tense and aspect. In this part, studies carried out by various scholars on these three concepts are reviewed and limitations of their researches are pointed out.Chapter Two is the theoretical basis of this thesis. In this part, the relationship between time, tense and aspect is discussed and different means of expressing past time, present time and future time are presented, at the same time, their usages are presented in detail.Chapter Three and Chapter Four are the backbone of the whole thesis. In Chapter Three, expository texts, descriptive texts, argumentative texts and narrative texts are studied. Ten texts are chosen from each kind of the texts. By... |