“Series of Teaching Foreigners Chinese Grammar” is the achievement of “Research and Development of Grammar Syllabus for Teaching Chinese as a Foreign Language and Teaching Reference Grammar Series (Multi-volume)”, a major project of National Social Science Fund of China sponsored by Professor Qi Huyang, which has been selected as the “2022 Founding Project of National Publication Foundation”. As an important reference book for international Chinese language education, it aims to build and improve the “Grammar System of Chinese Teaching” for foreign students to meet the development needs of the new era. It mainly serves the first-line Chinese teachers, researchers, graduate students and undergraduates majoring in Teaching Chinese to Speakers of Other Languages. This series consists of 39 volumes, including 4 outline series, 26 book series, 8 summary series, and 1 collection of essays.

This book is a fascicule of the third edition in the series of 26 volumes.

The Auxiliary Word “Le” highlights the close relationship between “le” at the end of the Chinese word and “le” at the end of the sentence, regarding the two as the distribution of the same individual marked in different positions. This book collects and sorts out a large number of problems related to “le” in second language teaching, and classifies them into five parts including “nature and function”, “connections and distinctions”, “combination and co-occurrence”, “errors and causes” and “teaching and practice”, and gives relevant analyses and explanations. The questions in each part are arranged progressively in order to help Chinese teachers or learners learning Chinese as a second language at different stages. The integration of these problems is a systematic and comprehensive review of the function, usage and teaching of the Chinese character “le”.

Presently, almost all teaching materials have arranged the teaching of “le” in the primary stage, and illustrated its functions and usage with examples, and teachers also pay particular attention to the teaching of “le” in the teaching process, but the error frequency of using “le” still remains very high, no matter in learners’ oral expression or written composition. Moreover, the wrong use of “le” does not only appear in the primary stage, but also popular in the intermediate and advanced stages.

This book has a very clear perspective on how to deal with specific problems. It proceeds from the perspectives of “nature and function”, “connections and distinctions”, “combination and co-occurrence”, “errors and causes”, and “teaching and practice” based on the principle of simplicity, which helps to simplify complex problems with strong operability.

It is recommended for front-line teachers of language education, language teaching researchers, and postgraduate students majoring in international Chinese language education and other language education.