Looming Sentence Preposition "in" Its External Han Teaching

The object of the study is the preposition "zai"which used in front of the sentence.Frist,the essay describes the object of this paper. research review. topics and the construction of this paper.After defining similarities and differences of prepositions of the omission and implication.Then it further clarifies the application and omission of the preposition "zai" used in front of the sentence and the semantic classification of "zai" phrase. There are 2 categories of the semantic classification of "zai" phrases:the concrete one and the abstract one; Whether the preposition of "zai" occur in front of a sentence or not ia s difficult issue that concerns semantic,syntax and pragmatic.The text regards the grammer veiws of three levels as the basics.and at the same time,refers to such modern linguistics theories as human emotion. "ge grammer",systematically studies the factors influcing whether the preposition "zai" occur or not.And then, the text summerizes and classifies the usage errors of the preposition "zai" and its corrective phrases in veiw of the theory of error analysis to analyze the causes of these errors.At the same time,It conbines the theory of whether "zai"occurs or not,kuanshijiec,the preposition teaching of TCL,representing some effective teaching strategies and enlightment to TCL.Finally it points out the Breakthroughs and shortcomings of this paper.