| The importance of context has been fully demonstrated in the development of linguistic study. And with the context research being continuously deepened and expanded, what we can know quite well is that the study of context is of not only theoretical but also practical significance for the entire linguistic study. Especially the classification and research on the functions of context, it is always a hotspot in linguistic. It has highly practical value for language communication and teaching to explore and utilize the functions of context. The purpose of the present study is trying to make a comprehensive and exhaustive research on explanatory function. And on the premise of that, we will interpret the effect of explanatory function in TCSL by using my teaching experience and the questionnaire method.In this paper we start with the research on the history and present condition of context, and make an overview in both context study and the context functions. And it is emphasized that the explanatory function can be seen in different classifications of the context functions. In the following, we study explanatory function in six aspects, such as phonetics, lexicolater, grammar, semantics, rhetoric and pragmatics. This is the ontology study of the paper. In the application study, the significance of context functions in TCSL is first expounded. Then base on the teaching experience, we make some research on linguistic context and Non-verbal context functions'application in TCSL. A questionnaire is used to investigate the language capability of the foreigner students in the International Education College of Huazhong University of Science and Technology, trying to find out something can be good to the teaching. Three strategies are proposed at last, including demonstrating and guiding the students to use explanatory function in class, some principles related, and enriching the students'knowledge of Cultural Context in from various ways. |