本文在分析“了”的专家语法规则的基础上，提出了教学语法编写的四原则，并据此对“了”的专家语法规则做了教学上的两级改造：第一级确定了对外汉语教学中“了”的语法项目，第二级对“了”的教学项目做了顺序层次的编排 Based on the analysis of the expert grammar rules of “the”, this paper proposes four principles of teaching grammar compilation and accordingly makes two levels of teaching reform on the “grammar” expert grammar rules: The first level identifies the foreign language Grammar project “in the teaching”, the second level of the “out” of the teaching program to do a sequence level arrangement