Ontological Study Status And Use In Foreign-Chinese Teaching Of "是(Shi)" And "的(de)"

是(shi)"and的(de)" are often used in our daily life, especially in Foreign-Chinese teaching, prep students also need to master it. But the part of speech and syntactic functions of’是.(shi)"and "的(de)" are very complicated, also do the semantic feature, it’s hard to distinguish. Although there are many research about this in the world, and got some achievement. But the researches lack of systematicness and standard nature. Each scholars do research from different point of view and aspect, each airs his own views, seldom consider about other aspects; or do comparison on the same aspect with different viewpoint., and seldom pay attention to the relations of different aspects. This paper is aiming to refining and systematizing the achievement based on the research of predecessors, and present own point of view. What more important, under the research in Foreign-Chinese teaching, predecessors only study the biased error in phrasing, and based on language database to analysis then offer the suggestions, but seldom to combine it with ontological study and analysis the reason of biased error. This paper is also aiming to combine the ontology systematic analysis research and the questions in Foreign-Chinese teaching, then use ontological study to solve the problems which are found in foreign-Chinese teaching, then give some reasonable and feasibility suggestions.This paper stars from ontological study, reviewed the part of speech, syntactic function and pragmatic conditions of "是(shi)"and "的(de)". From the basic point of view describes the situation of "是(shi)"and "的(de)" in contemporary Chinese language, and make preparation for sentence patterns of different grammatical functions and pragmatic conditions study of "是(shi)...的(de)", then offer the theoretical basis for error analysis which happened on overseas student in this paper.Then from noumanon selective analysed different formats of "是(shi)...的(de)" Structure, based on the research of predecessors, analysed and summarized the syntactic function and pragmatic conditions of each sentence pattern, then offer the own analysis and examination.Based on the sufficient of ontological study, used the HSK dynamic corpus sources of BLCU(Beijing Language and Culture University), and analysed the biased error of "是(shi)...是(de)" during the study of overseas students, then analysed the reason of biased error in ontological aspect.All the study and analysis are aiming to teaching better, so in the last part of the paper, I combined preceding research and moderate experiences, then offered some suggestions in the "是(shi)...的(de)" phrasing used in Foreign-Chinese teaching activities. The suggestions mainly come out from the written of teaching materials and coordinate with after class practice, explaining of teachers and reviewing consolidation after class.