The teaching of Chinese modal particles is one of the difficulties in Teaching Chinese as a Second Language because of the intangible meaning of Chinese modal particles.The study on the errors of Chinese modal particles is an important one for Teaching Chinese as a Second Language.Based on the investigation of Brazilian students’ errors in using the Chinese modal particles "ma, ne,ba, a, de, le",the thesis analyzes the errors and discusses the reasons of the errors,then provides some available teaching strategies. There are five sections in this article.The first section is the introduction. First,the purpose and the object of this research are introduced briefly. Second,the researching results about the modal particles and the teaching of the modal particles in TCSL are summarized. At last,the theory and the research methods of this subject are introduced,and then the object and the content of the investigation and the source of language materials are explained.The second section is the investigation of the present situation of modal particle teaching in TCSL in Brazil.The the content of modal particle in syllabus and the Chinese textbooks to Portuguese-speaking students, and the teaching of modal particle in Brazil are respectively investigated.The third section is investigation of the Brazilian students’ errors of Chinese modal particles "ma, ne, ba, a, le, de".First, the questionnaire and standard of error confirmation are explained, and then the investigation results are analyzed, the overall situation and individual modal particles are respectively analyzed. Then the errors of each modal particles are respectively analyzed according to four different types of errors:omission, addition, misuse and sequence error. Then the causes of errors are analyzed, there are the following four reasons:negative transfer, target language generalization, the affect of learning and communicative attitude, the affect of teaching and teaching materials.In the fourth section, the suggestions about teaching strategies and the writing of teaching materials are provided. The suggestions for teaching strategies are:the classification of modal particles by their difficulty levels, progressive teaching; contrast of different modal expression in Chinese and Portuguese to help the students to establish association; the use of comparative pedagogy in Confusing modal particles; the use of scenarios teaching methods; association of modal particles and the sentence pattern; Periodic summary. Some suggestions about the writing of teaching materials are provided.In the fifth section, the discussions of the full text are summarized.The innovation of this thesis is that the investigation is a Brazilian students-oriented investigation, and the similarities and differences between Chinese and Portuguese modal expression are compared and analyzed, and some teaching strategies are suggested for TCSL to Portuguese-speaking students. |