1 Introduction

This article introduces the importance of Form Focused Instruction (FFI) and its timing in second language teaching, explores the different effects of separated and integrated FFI on learners' explicit and implicit knowledge acquisition, and points out the shortcomings of current empirical research, especially in the study of the Chinese foreign language learning environment. The research objective is to analyze the effects of different FFI timing on the acquisition of explicit and implicit knowledge of difficult grammar points in Chinese junior high school English.

2 Literature Review

The literature review section explores the role of separated and integrated forms of focused teaching in second language acquisition and their impact on explicit and implicit knowledge. Separatist teaching separates the focus on language form from communicative activities, while integrative teaching focuses on language form in communicative activities. Both teaching methods involve explicit teaching, but the timing is different. Based on the theory of transfer appropriate processing, it is predicted that integrated teaching will help with knowledge retrieval that simultaneously focuses on language form and meaning, while separated teaching will help with individual language form testing. Explicit knowledge is conscious and declarative, while implicit knowledge is tacit and unconscious. The existing research results are inconsistent. Some have found no significant difference in vocabulary learning between separated and integrated teaching, while others have found that integrated teaching performs better in certain aspects. Spada et al.'s study compared the effects of two teaching opportunities on explicit and implicit knowledge, and found that integrative learning was more effective for implicit knowledge, while dissociative learning was more effective for explicit knowledge. However, existing research focuses more on explicit knowledge and examines less on implicit knowledge. In addition, the effects of pre separation and post separation in separation based teaching are also different. This study will further explore the impact of these three teaching opportunities on the explicit and implicit knowledge acquisition of difficult grammar points by learners at different levels.

3 Research Methods

Detailed description of various aspects of the research methodology. The research subjects are students from three classes in eighth grade of a middle school, who are randomly assigned and divided into different level groups based on median scores. The target grammar point is the comparative level between adjectives and adverbs, determined through teacher and student surveys. The experimental teaching process adopts different forms to focus on teaching timing, including pre separation, post separation, and integration into groups. The teaching materials and processes are strictly reviewed. The measurement methods include error correction testing and timed grammar judgment testing, both of which have good reliability. The experimental process includes pre-test, experimental teaching, and post test, and the teaching is completed by each English teacher. The data analysis adopts mixed analysis of variance and effect value calculation to detect inter group differences.

4 Research Results

In the error correction test, there was no significant difference among the three groups of learners in the pre-test. The post test showed that the high-level group improved more than the low-level group, and the pre separation group performed the best. The three factor mixed analysis of variance showed that testing time, grouping, and language proficiency had significant main effects, but no interaction effects. The low-level group scored significantly higher in the immediate and delayed post tests compared to the other groups in the pre separation group. The high-level group scored the highest in the post separation group during the immediate post test, and the highest in the pre separation group during the delayed post test.

5 Discussions

The different forms of focusing on teaching timing have different impacts on the development of learners' explicit and implicit knowledge. The pre separation type has a better effect on explicit knowledge for high and low-level learners, while the three types of teaching timing have similar effects on implicit knowledge. The pre separation type enhances explicit knowledge by clarifying learning objectives and focusing attention, while the integration type and post separation type have weaker effects due to cognitive development limitations and attention dispersion. In terms of implicit knowledge, there is no significant difference in the effectiveness between separated and integrated teaching methods, which may be related to the short experimental teaching time, learner age, and cognitive development level.

6 Conclusion

This study reveals the impact of different forms of focused teaching timing on learners' explicit and implicit knowledge acquisition. Research has found that the timing of pre separation teaching is more effective in enhancing learners' explicit knowledge, while the three types of teaching timing have similar effects on implicit knowledge. For middle school students, teachers should clearly teach grammar rules, especially for difficult grammar points. Adopting a pre separation teaching approach can help students communicate better. Meanwhile, teachers should promote the development of students' tacit knowledge by increasing communication activities.