This paper attempts to review and prospect the research on second language acquisition. In the process of review, a series of PLA theories are investigated, and Krashen's input hypothesis model is used in the comparative analysis of work. The advantages and disadvantages of these two models and their contributions to PLA research are discussed theoretically. This paper introduces the methodological research of PLA in recent years from the perspective, taking disciplines in neighboring countries as examples, such as linguistics, first language acquisition research, cognitive science and so on. , and gives theoretical linguistics and universal grammar within the framework of first language acquisition, and attaches great importance to the comprehensive research and investigation of the PLA. The article praised the study of the People's Liberation Army, which focused on interpretation, and considered it a major breakthrough.

(Google translation, for reference only)