A Comparative Study Of PPP Instruction And Input Processing Instruction In Acquiring The English Subjunctive Mood

English grammar teaching has become a thorny problem for the researchers and teachers, and grammar learning is also a key point for students. Most teachers use the output-based instruction in English classes of China, but few teachers use input-based instruction. There are many studies on English teaching methods. The studies on input processing instruction are becoming deeply but not enough.Therefore, on the basis of the previous research results and relevant literature, this thesis compares the processing instruction with 3P instruction to study the effect of requiring the English Subjunctive Mood.There are 121 senior high school students in Grade two taking part in the experiment. They came from three classes that are in the same level. The three classes were assigned randomly to two experimental groups and one control group. One of the experimental groups received the processing instruction and the other one received the 3P instruction. The control group did not receive any instruction. One week before the experiment, all the students of three groups took the pretest. Then the experiment groups were taught subjunctive mood as requirements. In the end, the three groups took the post-test immediately. Two weeks later, the three groups took the delayed posttest. Finally, the SPSS software was used to analyze the data. The finding are as follows:Firstly, the processing instruction is superior to the traditional instruction in promoting comprehension.Secondly, the effect of traditional instruction remains longer than that of processing instruction in production.Thirdly, the traditional instruction may promote comprehension and production.By the comparative study, it concludes that English teachers should call students’ attention to form and meaning and effect the incorrect processing strategies to make students form correct processing strategies. And this study proves the role of input that plays in the second language acquisition, and gives direction for the further research and teaching.