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A Brief Review of the Studies of Teacher Talk in Second Language Classrooms

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Introduction
Anton Semyonovich Makarenko, a Soviet educator, says that the effects of the same teaching method maybe 20 times different because of teacher talk. Generally speaking, the kind of language used by the teacher for instruction in the classroom is known as teacher talk (TT). For this term, Longman Dictionary of Language Teaching and Applied Linguistics defines it as "that variety of language sometimes used by teachers when they are in the process of teaching". According to Rod Ellis (1985), second language teacher talk is the special language that teachers use when addressing second language (L2) learners in the classroom. Teacher talk has 7 characteristics: 1) the teacher's speech speed seems to be a little slower; 2) the teacher's thinking pauses more frequently and longer; 3) the pronunciation is clearer and clearer; 4) the selected vocabularies are simpler; 5) the degree of subordination is lower (that is, the less use of subordinate sentences); 6) there are more straightforward and declarative sentences than interrogative sentences; 7) the teacher's self-repetition is more frequent (Chaudron C., 1988).
Language is the most important teaching tool for teachers and teachers' speech styles and changes will have a profound impact on teaching effects (Jeremy Harmer, 1998). Relevant research started in the 1950s in western countries and began in the late 1990s in China. On top of that, researches in this field grow rapidly and have a critical role in improving the quality of language teaching and promoting teacher development. Rod Ellis (1985) divides the studies of teacher talk into two types: those that investigate the type of language that teachers use in language classrooms and those that investigate the type of language they use in subject lessons. In this paper, I propose to have a review of the studies that investigate the first type, specifically, language that teachers use in second language classrooms, firstly from the perspective of teacher talk framework and then from the perspective of empirical studies in the three categories of linguistic function, medium-oriented function, procedural and regulative function.

A Review of Frameworks of Teacher Talk in Second Language Classrooms
The frameworks of teacher talk, based on the combination of past research results, play a key role in the study of teacher talk in language classrooms, giving guidance for future studies such as discourse coding. For instance, Flanders (1961) puts forward the FIAC framework (Flanders Interaction Analysis Categories), dividing

IRA-International Journal of Education & Multidisciplinary Studies
63 63 classroom speech acts into ten categories from three dimensions: teacher talk, student talk and other speech acts (such as silence). Later, Moskowitz (1971), based on the FIAC framework, proposes the FLINT framework (Foreign Language Interaction), subdividing teacher talk into twelve categories, including processing emotion, praise or encouragement, humor, using students' ideas, verbally repeating students' responses, questions, providing information, correcting mistakes, instruction, guiding drills, criticism of students' behavior and criticism of students' responses. Sinclair and Coulthard (1975) divide teacher talk into five levels: lesson, transaction, exchange, move and act. More significantly, based on the research, they propose the transmission mode of education: IRE (Initiation-Response-Evaluation), which was later changed to IRF (Initiation-Response-Follow up). Teacher talk is particularly evident in these two transmission modes so some researchers choose to compare their research results with these two modes like Xu and Ying (2002). Hall and Walsh (2002) argue that classroom talk mainly has three pragmatic functions: linguistic function, medium-oriented function, procedural and regulative function, followed by some researchers such as Ma and Liu (2013) in their article to classify and discuss relevant literature. In the following discussion in the 3 rd part, the explanation of these three functions will be presented with a review of some empirical articles from these three aspects. Though scholars have made great contributions to the improvement of frameworks, most of these studies have no consideration for the cross-linguistic applicability of these frameworks for analyzing foreign language (FL) teachers' target language (TL)/the first language(L1) use in contexts where FL instruction is Of course, some Chinese scholars have also put forward the frameworks of language teacher talk, such as Kang and Chen (2011). Based on the corpus research, they find that the past studies have ignored some functions of teacher talk such as scaffolding. In their new framework, there are four categories at the macro level: language input, implementation of teaching, classroom management and social communication, under which there are twelve dimensions respectively at the micro-level: demonstration, using students' discourse; direct explanation, initiation, leading in, prompt, question change, recognition, evaluation, direct error correction, corrective feedback, comment, development, clarification of the request, confirmation and verification; meta-instructions, instructions, nominations, summonses, incentives, and concluding remarks; turn marks, understand and verification, and maintaining discipline; conversation. In addition, Zhu Yan (2016) puts forward a multi-dimensional evaluation framework for the effectiveness of foreign language classroom discourse, including the consistency between classroom activities and teaching objectives, teacher discourse, student discourse, interactive participation forms, meaning/form-oriented turn and discourse structure. What's more, based on the theory of Vygotsky's zone of proximal development and scaffolding theory, Zheng Xinmin et al.
(2019) put forward the interaction interface of "discourse-discourse" "discourse-emotion" "discourse-meaning" "discourse-value" "discourse-activity" as the scaffolds for English teaching and a four-in-one teacher's classroom discourse construction system. Nonetheless, it's a pity that many researchers still carry out the studies based on the frameworks from western countries, for which Ma and Liu (2013) argue that the frameworks of language teacher talk given by domestic authoritative scholars in China should be taken into consideration.

A Review of Empirical Studies of Language Teacher Talk
Hall and Walsh (2002) divide classroom talk into three categories based on pragmatic functions: linguistic function, medium-oriented function, procedural and regulative function. Firstly, the linguistic function means

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that classroom talk is a style code for the comprehensible language input and output of second language acquisition, helping learners to have authentic and understandable language input and output under different contexts. According to Ma and Liu (2013), its research field contains basically the amount of teacher talk (as seen in Chaudron, 1988;Zhao, 1998;etc.) and more specifically, phonetics, vocabulary, grammar, text as well as provides guidance for teachers to correct themselves and help them to find out the deficiencies in their oral expression, which have important implications for the professional development of English teachers. Another case is from Jiang (2020). The research adopts Spencer-Oatey's Rapport-management Theory as the analytical framework and uses discourse analysis to analyze how EFL teachers utilize various kinds of meta-discourse resources to construct dynamic identity in the classroom, to maintain the teacher 's and students' face, and to realize the equality and association rights between the teacher and students for building teacher-student rapport.
Based on conversation analysis, Dong (2019) focuses on question-response sequences in academic micro-contexts, and examines a teacher's use of questions within the EFL classroom, following SETT (Self-Evaluation of Teacher Talk) procedures, critically evaluates and relates the teacher's questions and students' responses to samples of authentic interactions. Findings indicate that the L2 classroom is a dynamic and complex series of inter-related micro-contexts, in which meaning is constructed and negotiated by both teachers and learners. The interaction under each class mode is driven and promoted by different types of questions, through which a variety of pedagogical goals are accomplished, including passage comprehension, language use, and critical thinking. In this process, opportunities for learning are also jointly increased by the teacher's extended wait-time, direct repair, and feedback. All of these suggest that appropriate use of questions can create an atmosphere that is conducive to learning and is likely to promote learner involvement.
Secondly, the medium-oriented function refers to the negotiation of meaning, knowledge construction and language function development. In the second language acquisition, negotiation of meaning is often used to refer to the interactive adjustment made by teachers and students in order to eliminate their communicative show that the participants differed markedly from one another not only in the amount of target language(TL) used but also in the pedagogic functions they used most frequently and in the language (TL or English) they chose for these functions. There was a tendency by most teachers to avoid complex interactions in the TL, limiting the potential for intake and real communication on the part of the students. Implications are drawn for research and teacher education. They also contribute to the framework of teacher talk: a multiple-category coding system entitled "Functional Language Alternation Analysis of Teacher Talk" (FLAATT), which is developed expressly to allow a cross-linguistic comparison of the relationship between teachers' language choices and particular pedagogic functions. What can't be ignored is that the research about the linguistic function and the medium-oriented function are both closely related to teaching function and teaching effects.
Thirdly, the procedural and regulative function means that teacher talk has the function of organizing, managing and regulating classroom activities and language behaviors. There were many studies about the procedural and regulative function in the western countries, such as Christie F., 2002, but fewer studies in China.
For instance, from the perspective of Bernstein's teaching discourse theory, Liu and Zhang (2010) adopt the corpus research method to analyze the conventional discourse in middle school English classes in China.
Through quantitative analysis of teachers' directives, they find that in the class, teachers used more direct, less polite and more mandatory classroom instructions. The classroom has not yet realized the transformation from teacher-centered to student-centered advocated by the discourse of foreign language curriculum and teaching reform in China. With the help of the tool Citespace and then reading the articles in detail, I also have some critical thoughts.

Reflection on the Relevant Research in China
There are about one hundred and fifty relevant key articles from 1998 to 2020 in the CNKI (SCI, CSSCI, PKU, EI and CSCD). Based on the statistics, keywords in recent years' research of language teacher talk are teacher talk, classroom talk, teacher talk, discourse analysis, case study, foreign language class, college English class, college English teacher, target learner, strategy, sign language. Moreover, there are eleven keyword clusters: teacher talk, class type, questioning talk, reference question, corpus, Krashen, foreign language class, relevance theory, output optimization, discourse quantity. According to the data, the 2 nd keyword cluster (questioning talk) shows that most of the research focuses on the linguistics features (similar to the result of Ma and Liu, 2013); the 3 rd keyword cluster (reference question) and the 8 th keyword cluster (output optimization) indicate that research pays more and more attention to the development of students; the 4 th keyword cluster (corpus) reveals that Corpus is the trend of research tools in this field. There are, however, some problems. For example, research of the amount of teacher talk still occupies a large part; studies mainly happen in university classrooms; researchers tend to carry out the study and analyze based on foreign theories or frameworks like language environment theory and IRF in Xu and Ying (2002), interaction hypothesis and Swain output hypothesis in Liu which is yet lacking in China.
In addition, there are plenty of topics needed to be considered in this field. For one thing, the studies focus on teachers but the depth of domestic research in this field needs to be expanded. Teachers' language ability (including language background, fluency and other factors), discourse ability and cognitive ability should also be paid attention to. The application analysis of discourse can not be separated from considering the changes of people, things, places and times. For example, Li (2007), by using the discourse analysis method, compares the interaction patterns of the two types of college English classes, one instructed by native speakers of English, the other by Chinese teachers of English. It has been found that TST (Teacher Student-Teacher) pattern occurs more frequently in the classes taught by Chinese teachers of English. No significant difference has been found between the two types of classes in terms of the total frequency of the moves. Moreover, it has revealed that the exchanges initiated by students promote students' participation in classroom activities. The study has implications both for the organization of English teaching classes and for the employment of native English speakers as college English teachers in China.
For another thing, we cannot neglect other factors such as the influence of students. Henzl's study of teacher talk (1979, cited from Ellis R., 1985) has shown that the teachers adjust their speech rate in accordance with the listeners' proficiency. That is, teacher talk is dynamically tailored to learners' needs, affording them increasingly richer input as they develop. Li and Zhao (2016) argue that the qualified output generated in the classroom interaction relies on the negotiation of meaning. Some English teachers, however, tend to avoid negative feedback during the course of negotiation, which is not helpful for output production and leads to fossilization as well. Teachers ought to have a proper perception of "classroom interaction", make full use of negotiation devices, and thus help students generate qualified output. Meanwhile, advanced technology should be applied and the form of output should be diversified.
Additionally, researchers need to consider the impact of teaching contexts and the output of teacher talk. Some researchers look more carefully at the different types of lesson types such as writing class (like Ewert D. E., 2009). For instance, Lv and Wang (2013) employ both qualitative and quantitative methods to conduct a reflective analysis regarding Teaching Resource Platform in college English teachers' classroom discourses in terms of the amount of teacher talk, teachers' questions and feedback. The results indicate that this student-centered model helps promote effective negotiable interaction, plays an important role in heuristic teaching and development of second language acquisition, paving the way to the realization of the model of a flipped classroom.
Interestingly, now there appears a new perspective for the research: critical discourse analysis. That is, based on the critical discourse analysis of teacher talk, researchers want to find out the unfair issues, aimed at improving the relationship between teachers and students so as to better promote the development of students.
Under the curriculum reform in China, it is worth noting that with the introduction of the Core Competence of English Discipline in 2017, the research field of English teaching in primary and secondary schools has undergone changes. As a result, the study of language teacher talk can also be considered from the perspective of the Core Competence of English Discipline which includes four parts: language ability, learning ability, cultural awareness and thinking quality.

Conclusion
Through the overall review of the studies of second language teacher talk from the perspective of framework and then from three categories, followed by the comparison of studies at home and abroad, it is of significance to enhance the research in primary and secondary schools in China and consider the frameworks of teacher talk given by domestic authoritative scholars in China. Furthermore, there are still many topics that researchers can pay attention to, such as language selection and conversion, language ability, other time of teacher talk (play time; silence), lesson type (listening and speaking, reading and writing) etc. There is a lack of research deep into language teachers' discourse awareness and competence in China.