1. Introduction

Classroom interaction is jointly managed by teachers and learners, but their contributions are asymmetric, with teachers typically playing a primary role and learners having limited participation. With the increasing understanding of the social dimensions of second language learning, researchers have begun to focus on learners' participation in the classroom learning process. Language is a fundamental tool for teachers to manage classroom interactions, so any attempt to increase learner engagement should start with investigating teachers' language use. The literature has fully documented the impact of teacher language use on learner engagement and second language learning opportunities, but mainly focuses on the Indo European language family, especially English, with relatively limited understanding of other languages such as Chinese. Due to the differences between Indo European languages and Chinese, the applicability of existing second language research results to Chinese has been questioned, highlighting the need for more research in this field. In the past decade, the teaching and learning of Chinese as a foreign language has experienced dramatic growth in many countries and regions, but this growth has been accompanied by various challenges. The unique pronunciation system of Chinese is extremely challenging for non-native speakers, and teaching Chinese as a foreign language mainly adopts a teacher centered approach, which is inconsistent with local Western educational practices, resulting in poor learning experience for Chinese learners, thereby reducing learning motivation and even causing learners to give up further learning. Therefore, the need to improve Chinese language teaching and learning is evident. Various efforts have been made, such as teacher training and professional development, innovation in Chinese teaching methods, and acquisition of specific Chinese grammar. However, few people pay attention to the classroom learning process, especially issues related to teachers' language use and learners' participation. In this context, this study aims to fill this gap by exploring the impact of teacher language use on learner participation in Chinese as a foreign language classrooms. Guided by socio-cultural theory and using reflective methods, this study helps teachers observe, evaluate, and reflect on their teaching in a systematic manner. The research results are expected to provide Chinese language teachers with information on how to make their language use more effective in Chinese teaching and learning.

2. Theoretical framework: A sociocultural perspective on L2 learning

Explored second language learning from the perspective of socio-cultural theory. Sociocultural theory suggests that human cognitive development, including second language learning, is a social activity rather than an individual activity. Vygotsky proposed that cognitive development has two interrelated but different levels: actual development level and potential development level. The gap between the two is called the Potential Development Zone (ZPD), which needs to be bridged through teaching to promote learning. The mediating role in the learning process is crucial, as experts use various tools to assist individuals in completing functions that were initially impossible, with language playing an important role as a symbolic tool. Language is not only a tool for communication, but also a cognitive tool for shaping and reshaping our thoughts. The second language learning from a socio-cultural perspective requires learners to construct their own second language knowledge through dialogue with other participants, thereby advancing their ZPD. This socialized and mediated learning perspective has a profound impact on second language classroom teaching and learning. Under this approach, teaching is no longer a linear process of knowledge transfer from teachers to learners, but rather an auxiliary process in which teachers help learners continuously improve their ZPD. Vygotsky believes that teaching is only effective when it triggers a series of functions that propel learners forward within the ZPD. This requires teachers to create sufficient space for learners to practice their second language skills, in order to bridge the gap within ZPD. Given that language is a fundamental tool used by teachers, the quality of language use by teachers directly affects learners' engagement and subsequent opportunities for second language learning. Considering the purpose of the current research, the following review is conducted in the context of socio-cultural theory.

3. Literature review

Reviewed relevant research on teacher language use and second language learning. Ant ó n (1999) studied the impact of teacher centered and learner centered discourse in second language French classrooms and found that learner centered discourse provides learners with more opportunities to participate in the learning process. Smiley and Ant ó n's (2012) study also suggests that teachers' language use is crucial in encouraging learners to expand their second language skills. Van Compernolle (2010) found that teacher discourse directly affects the incidental micro development of second language French learners, that is, teacher language use is directly related to second language learning opportunities. Walsh and Li (2013) and Da ş kin (2015) explored the strategies used by teachers in second language classrooms to promote learner engagement.

4. Methodology

Introduced the research methodology, including the definition, characteristics, and cyclical process of action research, as well as the background, participants, data collection, and analysis methods of this study. Action research is a self reflective exploration aimed at improving the effectiveness of teachers' teaching practices. This study was conducted in a primary Chinese language classroom at a university in Denmark for two semesters, with a focus on developing oral skills. The teacher is a Chinese native speaker with four years of teaching experience in Denmark, mainly using English for teaching. There are a total of 15 participants, except for one Lithuanian student, all of whom are native Danish speakers aged between 22 and 29. They attend 90 minute classes per week for 10 weeks per semester.

5. Findings

By using microscopic analysis methods, the analysis results of the data were presented for two research questions. Due to space limitations, the following findings focus on several representative excerpts. Research has found that teachers' language use has three characteristics in promoting learner engagement: shaping learners' contributions, providing interactive spaces, and involving learners in problem-solving. These characteristics appear at different frequencies (see Table 1). At the same time, these characteristics are not independent of each other and sometimes intertwined in one excerpt.

6. Discussion

The relationship between the use of classroom discourse by overseas Chinese language teachers and learner participation was discussed, and analyzed from the perspective of socio-cultural theory. The research findings indicate that teachers' language use directly affects opportunities for second language learning. Specifically, when teachers continuously shape learners' discourse through strategies such as detailed questioning, clarification requests, translation, emphasis, recasting, and confirmation checks, they create more opportunities for learners to participate in understanding their own discourse. This provides support for previous research. From the perspective of socio-cultural learning, these language use patterns of teachers not only activate learners' zone of proximal development (ZPD), but also extend it to higher levels, enabling learners to produce discourse in a targeted manner. This achievement indicates an improvement in learners' second language proficiency, which may not have been achieved without their participation.

7. Implications for CFL education

The importance of self reflection in enhancing teachers' teaching practices was emphasized, and it was believed that reflective practice is an effective tool for improving second language classroom teaching. It helps teachers to critically think about their own behavior, become aware of their teaching behavior, and build their professional knowledge. Especially for Chinese language teachers with a Chinese educational background, their cultural beliefs have a significant impact on teaching behavior, which is difficult to change even in new and different environments. This influence may explain why the teacher centered approach is still popular in many Chinese language classrooms. Therefore, in order to achieve fundamental changes in Chinese language teaching, it may be more important for teachers to reflect on their teaching practices than blindly adopting so-called effective methods in English teaching.

8. Conclusion

Summarized the research on the impact of overseas Chinese language teachers' classroom discourse use on learner participation. Based on the perspective of socio-cultural theory, the study found that the use of teacher discourse can shape learners' contributions, create interactive spaces, and involve learners in the problem-solving process, thereby promoting learners' cognitive participation in constructing second language knowledge and providing more opportunities for learning. On the contrary, when the use of teacher discourse restricts learners' reflection on their second language use and interrupts their discourse flow, it hinders learners' participation in interaction and misses learning opportunities. The study emphasizes the role of teacher discourse in second language teaching and learning, as well as the value of reflective practice for the professional development of second language teachers. However, there are limitations to the research, including the nature of cross-sectional studies, the use of a single data resource, and the dual role of researchers as both teachers and researchers. Nevertheless, the research provides insights into how Chinese language teachers can use the language more effectively, which is of great significance for Chinese language teaching both domestically and internationally.