A Comparative Study of Multimodal Discourse in Grammar Teaching Between the Chinese Novice Teacher and the Experienced Teacher--Take Ba-Construction as an Example

. Based on the framework of multimodal discourse analysis, this paper uses ELAN 6.2 to annotate and quantitatively analyze the characteristics and differences in the use of multimodal discourse in the teaching videos of "Ba"-construction between a Chinese novice teacher and an experienced teacher. The results showed that among the four modal types, both the novice teacher and the experienced teacher used more behavioral modalities. With essentially the same teaching sessions, there was also consistency in the choice of modality. Environmental modality was used throughout the teaching. In the grammar teaching of the experienced teacher, the auditory modality was the main modality, and students made a lot of effective discourse output. He was good at using facial expressions and hand movements to guide students’ learning and creating a good learning environment. Teachers were more inclined to use hand movements (indicative) to guide students' learning and convey clearer and more explicit messages. Grammar is taught through the judicious use of appropriate modalities or multimodal combinations in each teaching session. This study can provide some reference for the development of teachers' grammar teaching in international Chinese education.


Introduction
The "Ba" construction is a special and common basic sentence form in modern Chinese, which is a hot topic in research and a challenging point in teaching. Relevant research findings are abundant. The ontological research is very rich, including the syntactic structure (Cui, 1995), pragmatic features (Li and Wang, 2001), and semantic features (Lai, 1924;Wang, 1943). In terms of teachinglearning research, it involves the error analysis of "Ba" construction (Wei, 2006), teaching design and strategy (Zhao, 2006), acquisition research (Huang and Yang, 2004), etc. Although the theoretical research of "Ba" construction is fruitful, the teaching effect of "Ba" construction in actual Chinese teaching is not satisfactory. Also, students often use avoidance strategy in oral communication, and tend to use simple sentences and words or gestures to express their meaning. In written language, they do not initially choose "Ba" construction to express, and prefer to use multiple simple sentences that are less likely to make mistakes instead of "Ba" construction. Students still make mistakes in using the "Ba" construction. This is largely since international students haven't grasped the "Ba" construction well. Therefore, the problem of how to make international students use "Ba" construction correctly in classroom teaching has become a problem for the academic community. Teachers play an important role in teaching. The experienced teachers are capable to grasp the rhythm of the teaching with clear teaching steps and various teaching methods, and the teaching efficiency of the class is relatively high. For novice teachers, "Ba" construction is still one of the more difficult grammar points to teach. Actually, the teaching process of "Ba" construction involves images, texts, audio, action, expressions and other modalities, which have strong multimodality. The selection of these modalities and different modal combinations can improve teaching and learning, which is conduction to stimulate teachers' motivation and creativity, to maximize the opportunity to learn. However, the current research on teaching "Ba" construction based on multimodal discourse analysis is extremely limited. The research in this area needs to be strengthened urgently. This paper draws on the framework of multimodal discourse analysis [Multimodal discourse analysis is a new theory emerging in the West in the 1990s, based on systemic functional linguistics (Halliday 1985, Halliday & Matthiessen 2004, Martin 1992 and Social Semiotics (Kress & Van Leeuwen 1996, 2001. Multimodal discourse theory has been applied to various fields such as advertising, culture and film, and has also provided a new perspective for disciplinary teaching and research.], observing the novice teacher and the experienced teacher's teaching videos of "Ba" construction, summarizing the multimodal discourse factors, the choice of teaching modalities and their combination, individual characteristics and differences. In this way, the impact of multimodal types on grammar teaching is explored to enrich the content of grammar teaching. It also makes suggestions for novice teachers to find more effective and operational ways of teaching grammar.

Research Questions
This study investigates and analyses the following aspects: 1) Summary of the multimodal discourse factors; 2) Comparison of the choice of teaching modalities and their combination between the novice teacher and the experienced teacher; 3) Individual characteristics and differences.

Research Objects
This paper is an empirical study based on video analysis. The content of this study is "Ba" construction. Classroom videos are analyzed in detail as the research corpus.The video of the novice teacher is from the public classroom videos on the Internet, with a total length of 9 minutes and 14 seconds. The video of the experienced teacher is derived from the "Teaching Cases in the International Chinese Language Classroom: Elementary Comprehensive Course" (The Research Group of International Chinese Language Classroom, 2016). This product is an action guide for novice teachers' classroom teaching, and the teaching process and steps are operable and replicable. The total length of the experienced teacher's video is 16 minutes and 55 seconds.

Research Tools
ELAN analysis software was used in this study to locate, annotate and count modal symbols from multiple perspectives and levels. The advantages of this annotation software are as follows: it supports multi-layer annotation of video data according to the time axis, can generate independent annotation files, is conducive to annotation centralized management and analysis, and provides a series of supporting functions for multimodal studies (Lin, 2019). ELAN 6.2 was used in this study.

Modal Coding
Referring to the classification of multimodality by Chen, Wang (2017) and Wang, Liu (2020), combined with the actual investigation of the video content, this paper identifies the types of modality and the multimodal symbols contained in each type, and defines the specific modality types to which the corpus belongs, conducts annotation and statistics, and analyzes and compares the use of each modality. The modal codes are divided into four categories, including visual modality, behavioral modality, auditory modality, and environmental modality (as shown in Table 1). El Visual modality is divided into three levels: pictures, texts and objects. Pictures mainly include pictures on PowerPoint (Vpp) and pictures on paper (Vpi). The behavioral modality mainly includes teachers' facial expressions, leg movements and hand movements. The teachers' facial expressions include raised lip corners, furrowed eyebrows, smiles, and expression in one's eyes, etc., which can output a lot of specific information that is difficult to express in language. Leg movements mainly refer to the teachers' body movement in the classroom, and hand movements have both instructional and noninstructional meanings. Auditory modality is used throughout the whole teaching, including teachers' discourse, students' discourse and teacher-student shared discourse. Teacher-student discourse refers to the situation in which teachers and students read aloud together in practice. Teachers' discourse includes explaining knowledge, giving instructions and giving feedback. Students' discourse includes oral exercises, questions, etc. Environment modality is used to change the distance between the teacher and students by the teacher moving around the classroom. This modality is also used throughout the whole teaching. According to Kress & van Leeuwen (2001), the spatial distance between people can be divided into five types: public distance, formal distance, informal distance, personal distance and intimate distance. Classroom teaching mainly includes two types: first, the close contact between teachers and students, i.e., in the student practice session, teachers observe students' learning by drawing closer, etc.; second, the long distance between teachers and students in the rest of the teaching stages, such as the distance between students in their seats and teachers standing on the platform.

Data statistics and comparative analysis
Based on the teaching videos, grammar teaching can be roughly divided into five stages: introduction → explanation → practice → classroom activities → summary → homework assignment. In order to compare the use of different modalities by the novice teacher and the experienced teacher, quantitative indicators such as the number of modal annotations, average annotation duration, total annotation duration, and the percentage of modal duration in the total length of the video were calculated to compare the actual situation of "Ba" construction teaching by the novice teacher and the experienced teacher. By comparing the number and average duration of each modal symbol, it can be concluded which modality types the novice teacher and the experienced teacher prefer. However, since the video duration of the two teachers is different, the total duration of the modality usage is only for reference. Through the percentage of the used modality in the total length of the video, we can see the importance and role of the modality in teaching, so as to understand the teaching characteristics of the Chinese novice and experienced teacher, and provide a reference for future grammar teaching.

Visual Modality
As can be seen from Table 2, overall, the number and type of various visual modalities used by the experienced teacher were more than the novice teacher. Specifically:  13. The experienced teacher is good at using texts on PowerPoint to summarize. Texts on PowerPoint was used throughout the teaching of both experienced and novice teachers, and the novice teacher relies more on texts on PowerPoint than the experienced teacher for teaching. Texts on PowerPoint was used to display the summary and assignment session. During the session of explanation and summary, both teachers used a series of exercises and examples to display the PPT text, highlighting the key points by using different fonts, colors, graphics and markers, which had the effect of emphasizing and summarizing, and facilitating students' understanding and memory. For example, the experienced teacher puts example sentences to display, and the dotted box marked with the same elements, "Ba" word is identified by blue, verbs are identified by green," 别 (don't )", "没有 (not have)" and other elements to use red to identify, finally the whole sentence bold amplifier. The experienced teacher asked students to read aloud, to familiarize themselves with language points (see Fig. 1). Thus, on a slide, all examples and sentence formats were displayed, and were clear at a glance, which was convenient for students to discover and summarize the rules. The novice teacher showed a simple example and a format, used signs such as the plus sign and arrow, which was less summative than the presentation method of the experienced teacher (see Fig. 2). The novice teacher used the most physical objects, but lack the three modal symbols of texts on the card, texts on the board. The experienced teacher's card text and board text were mainly used in the concluding stage, where the skilled teacher used the board to review the grammar format of the lesson. The texts on the card mainly include "放 (put), 贴 (paste)..." and "已经 (already), 别 (don't)... "and other adverbs commonly used in "Ba" construction. This way to clarify the position of the verbs and adverbs in the "Ba" construction, deepen the impression of students. The novice teacher used texts on PowerPoint directly to review and summarize during teaching (see Fig.  3). During the class of the novice teacher, summaries and assignments were also completed by texts on PowerPoint (see Fig. 4). In Chinese teaching, texts on the blackboard is still very important. It has "focusing", "strengthening" and "summarizing" effect (Cai, 2001), which can attract students' attention, facilitate students' understanding and memory, and increase their willingness to communicate.  The experienced teacher makes reasonable use of pictures on PowerPoint and pictures on paper. The average length of time spent using the PPT pictures was also longer for the experienced teachers than for the novice teachers (42.3s vs. 38.5s). Both teachers used the pictures mainly in the grammar practice stage, where the experienced teacher showed the pictures and the students practiced using the "Ba" construction they had learned based on the information from the pictures. The experienced teacher also brought out paper pictures, such as pictures of closets and rooms, and showed them to the students for group interaction to organize their classroom activities (see Fig.  5). Such visual teaching tools enable students to experience the learning activities more deeply and learn to learn by example. In contrast, the novice teacher didn't use paper pictures throughout the teaching process; they all used PPT pictures for explanation and practice, which were rather homogeneous (see Fig. 6).  The experienced teacher uses a greater variety of objects. Both the experienced and the novice teacher used physical objects. The average time of the novice teacher was longer than that of the experienced teacher (30.2s vs. 13.8s), which was mainly used in the examples and practice stages. The novice teacher used books, paper, pens and bags to help students practice "Ba" construction. The experienced teacher used passports, maps, notebooks, wallets, money and chairs in turn. Although the average time of objects was shorter than that of the novice teacher, more kinds of objects were displayed in the limited time, which maximized students' learning opportunities and enhanced the teacher's input and students' output.  Table 3, among the behavioral modality, the experienced teacher used this modality type more times than the novice teacher (157 times vs. 66 times). Hand movements were the most used and facial expressions were the least used. In the leg movement, the two teachers mainly used walking in the classroom, in order to meet the needs of teaching. Leg movements were more frequently used in students' grammar exercises because teachers need to interact with students, show pictures, and guide students to practice, etc. Hand movements (indicative) were also used more often by the experienced teachers (53 times vs. 49 times) than hand movements (non-indicative), while the opposite was true for the novice teachers (21 times vs.28 times). Specifically:

Behavioral Modality
The experienced teacher uses more hand movements (indicative). The use of hand movements (indicative) by the experienced teacher is mainly reflected in the practice stage. Since many pictures, texts and objects were used in the process of practice and group activities, it is necessary to use hand movements to guide and prompt. For example, when showing pictures, the experienced teacher usually stood in front of the PowerPoint with five fingers together to point to the pictures and words, instructed students to look at the content shown by the teacher, hands from top to bottom, and further pointed out the details so that students can quickly notice the teaching content ( Figure  7). During practice, the teacher also hands up, five fingers together to point to the students, and asked the students to answer questions, sometimes with teaching aids to indicate, that the movement range is larger. To observe the hand movements of the novice teacher (indicative), the novice teacher likes holding teaching aid for instructions. The novice teacher likes standing beside the PowerPoint, action from far to nearby walking, and most of the time the teacher only indicated the content shown in practice stage. Her action was single, movement range was small, kept hands most of the time in front of the chest and waist position (see figure. 8 & figure. 9). Teachers' gestures play an important role in classroom teaching. Appropriate use of hand movements in class can clarify the teacher's instructions, help students understand the requirements and content of the class, while allowing them to focus more on the content of the lesson. The novice teacher and the experienced teacher both use facial expressions. In terms of the use of facial expressions, the proportion of time spent by the experienced teacher on videos was higher than that of the novice teacher (3.66% vs. 2.79%). The facial expression both teachers used most of the time is a smile. Teachers' facial expressions are generally used together with auditory and behavioral modalities. For example, the experienced teacher used hand movements, facial expressions and teacher's discourse together when practicing. It is conducive to creating a comfortable learning environment for students. Teachers often use smiles in the stage of grammar introduction, practice and explanation. Smiles can be used to show their expectation and interest in students, and some smiles are interesting and satisfied with students' answers. " If teachers use smiles appropriately in teaching, they can motivate students to increase their interest and thus greatly improve their learning efficiency" (Guan, Liu, 2008). Smiling plays an important role in teaching: it can create a relaxed learning atmosphere, shorten the distance with students, and give feedback on the effects of learning. The following example can show how the experienced teacher respond to the students' reply. Teacher: 这是马可，他长得怎么样？ Zhè shì Mǎkě，tā zhǎng de zěnmeyàng ？ This is Mark, how dose he look like？ Student: 很帅。 Hěn shuài.
Very handsome.
In this excerpt, when students replied, "很 帅。 (Very handsome.)" The teacher smiled at the students' answers. The experienced teacher also had some expressions of doubt and enlightenment, mainly in the stage of grammar practice. For example: In this excerpt, when the teacher asked students questions, he had expressions of doubt and eyebrows raised (see Figure. 10). After hearing students' answers, he had expressions of enlightenment and relaxation. Facial expressions were also used in conjunction with other modalities to create an immersive learning environment and to stimulate the students thinking. These are all lacking in the novice teacher (see Figure. 11).  As can be seen from the ratio of auditory modality in Table 4, the percentage of teacher's discourse time of the experienced teacher in total video time was less than that of the novice teacher (39.2% VS 59.6%), while both student's discourse and teacher-student's discourse were more than that of the novice teacher. The teacher's discourse was involved throughout the whole teaching process, from the introduction to the final assignment. The teacher's discourse was embodied in the introduction, questioning, instruction, feedback, interaction and explanation. Students' discourse was present through the practice, explanation and summary of grammar teaching, which was embodied in answering questions, reading, expressing ideas and practicing. In the teaching of the experienced teacher, especially in the students' practice and autonomous activities, students' discourse lasted for a long time; However, in the teaching of the novice teacher, student discourse and teacher discourse were often spaced and fragmentary. There was basically no large period of student discourse, and students' independent inquiry exercises were lacking. "In order to improve the teaching effect, a studentoriented interactive communication mode is used to highlight the students' subject position in specific contexts" (Yu, Liu, 2008). The experienced teacher's teaching methods present "students play the main role with the dominance of teachers." in the classroom, by teacher's appropriate guidance, using a variety of teaching methods to involve students in the classroom, students are required to understand, speak, and practice as many times as possible, so as to achieve the goal of grammar teaching, improve teaching efficiency and effectiveness, embodies the principle of "succinctly and training". At the same time, the common discourse between teacher and students appeared in the practice stage. The following example can show the common discourse between teacher and students: Teacher: 马可请店员做什么? Mǎkě qǐng diànyuán zuò shénme ? What did Mark ask the shop assistant to do? Teacher & Students: 把花送到他的女朋友家。 Bǎ huā sòng dào tā de nǚpéngyou jiā. Send the flowers to his girlfriend's house. Teacher: 很好。 Hěn hǎo. Very good. In this excerpt, when asked the question, the experienced teacher paused a little, then slowly said the answer with the students. The teacher and students explore knowledge and practice together, becoming "partners" at this point, which facilitates students' full integration into the classroom, and guides students' effective output. 15 As can be seen from table 5, the environmental modality time ratio of the novice teacher and the experienced teacher were similar. The "close distance" all appeared in students' practice and group activities. Teachers walked into students for close observation, guidance and interaction. The "long distance" appeared in the stages of introduction, explanation and summary. At this time, due to the relationship of teaching equipment, it is generally necessary to stand in front of multimedia for instruction and explanation. At the same time, it also appeared in the practice stage. When taking out the objects, it will first show the students at a distance, and then carry out the close exercise. For example, the experienced teacher first showed the object "wallet" at a distance, and then closed the distance, put the wallet on the student's desk, and practiced the sentence pattern "S+把+O.+放在+地方 (S+ put +O.+ in + place)". The proper transformation of close distance and long distance can avoid the monotony of teaching, and also timely play the role of raising students' attention, which is conducive to the use of other modalities and create a good learning atmosphere. The common. On the whole, there are some common features in the grammar teaching between the novice teacher and the experienced teacher, which are mainly reflected in the following: First, among the four modal types, the behavioral modality was used more often to show and explain the "Ba" construction through various behavioral actions; the environmental modality was used less often, but it was longer because it was used throughout the teaching, always in conjunction with the classroom and other modalities. Second, the teaching sessions were basically the same, and the modality selected in different teaching links were consistent. For example, in the introduction stage, students tend to choose auditory modality to attract their attention and prepare to enter the grammar stage. Exercises and classroom activities tend to choose a variety of modal combinations to show grammar points so that students can be familiar with and use grammar points to express themselves. Texts on PowerPoint were often used to summarize the grammar format of "Ba" construction, which was convenient for students to learn and memorize. Thirdly, the environmental modalities were used throughout the teaching. According to the teachers' teaching characteristics, content and needs, in different teaching sessions, reasonable environmental modalities are adopted to coordinate with other modalities. For example, in the stage of practicing "Ba" construction, because of the need to guide students to learn, the novice teacher and the experienced teacher would close the distance and communicate with students, and it was convenient to display actions and objects; in the introduction, explanation, summary and other sessions, because the need to cooperate with the use of teaching aids on the platform to instruct students, so teachers and students kept a distance; When using behavioral modality, sometimes it was necessary to cooperate with students, teachers are drawn close to interact with students, which is more intuitive.

Discussion
Difference. There are also some differences in grammar teaching between the novice teacher and the experienced teacher, mainly reflected in: First, from the perspective of the frequency of use, the auditory modality is the main modality used by the experienced teacher in the teaching of "Ba" construction. Students' discourse is the most commonly used modal symbol. Through grammar exercises and classroom group activities, the experienced teacher encouraged students to use the "Ba" construction more to express themselves, speak more and practice more, and try to avoid the phenomenon of deliberately avoiding the use of the "Ba" construction in future oral communication. It can be seen that the experienced teacher took into account the interaction between teacher and students, and the teaching content and activities were to serve students. In the grammar teaching of the novice teacher, behavioral modality is the most frequently used modality. The novice teacher gave students more content and instructions but output less discourse. Lack of interactive practice may affect the final teaching effect. Students are the main role of learning, and teachers play a leading role. Teachers' proper guidance and practice are all aimed at letting students master grammar knowledge, guiding students to output effectively and focusing on the cultivation of their communicative ability. Second, the experienced teacher is more adept at using texts on PowerPoint, pictures on paper and blackboard writing to teach. They summarize the complex "Ba" construction, refine and sublimate the grammar so that students can understand it at a glance, which is lacking in novice teachers. The experienced teacher uses more diverse objects in the training stage, which can meet the needs of students' practice and enrich the teaching content. Thirdly, the experienced teacher is more inclined to use hand movements (indicative) to guide students' learning with a greater range of all movements and a clearer and more explicit message. The novice teacher, on the other hand, has a smaller range of movements, and most of their hand movements are confined to their chest and waist, making them more restrained in the classroom. The experienced teacher has richer facial expressions, which can attract students' attention and create a relaxed learning atmosphere by cooperating with other modalities. Suggestions. Through comparative research, some suggestions can be put forward for novice teachers in grammar teaching: Create an immersive language learning environment. Teachers will not always be in a certain position in the classroom, but will have reasonable position changes according to teaching needs. By working with environmental modalities and appropriate facial expressions, students' auditory, visual, tactile, and linguistic systems are mobilized to establish a harmonious classroom atmosphere. The use of multimodality should follow the principle of optimization and minimization. Teachers need to output effectively and reduce the complexity of information output. The experienced teacher creates optimized teaching content through the combination of traditional teaching tools and modern multimedia teaching tools, such as texts on PowerPoint, blackboard writing and texts on the card. Although multimedia develops rapidly at present, it plays an irreplaceable role in improving the teaching effect and quality, we cannot abandon the traditional teaching method, we should choose the most appropriate method according to the characteristics of students and teaching content, so as to maximize the advantages and avoid the disadvantages. Students strongly approve of writing Chinese texts on the blackboard, which has a great influence on the communicative intention in class (Wang, Zhou, 2021). Therefore, multimodal symbols should cooperate to improve the teaching effect. For example, when teachers use hand movements to display, because the movements are not easy to be recorded, teachers generally use PowerPoint, blackboard writing and other modal matching to assist, flexibly mobilize various modal resources to deepen students' impression, refine teaching content and improve students' learning efficiency. Create interactive classes, improve the proportion of students' discourse output, and encourage students to actively participate in the classroom and speak boldly through reasonable modal combinations. Krashen (1982) believed that an important condition for learners to acquire a second language successfully is to receive a large amount of language input conforming to the level of "i +1". Auditory input has the largest amount of information and the most direct transmission. Therefore, the high-frequency use of auditory modality by the experienced teacher is consistent with the characteristics of grammar teaching, which can run through every session of teaching and create a large amount of language input. Therefore, teachers can use their words to influence students, motivate them to learn, provoke them to think, and engage them more actively in learning practices.
Consequently, grammar teaching sessions should be carefully designed, layered, and reflected by appropriate teaching modalities to maximize students' learning opportunities and highlight teaching features. Through the use of appropriate modality or multimodal combination in each teaching session, the experienced teacher allows each student to participate in the class, improves students' interest and enthusiasm in learning, and realizes situational teaching. The strategy of "Maximize Learning Opportunities" (Kumaravadivelu, B., 1994) believes that as a teacher, it is our most important task to provide students with as many learning opportunities as possible.
The experienced teacher uses single modality and multimodal combinations to provide students with multichannel input, pay attention to the diverse use of the visual modality and behavioral modality, and let students produce a lot of output. This is consistent with the principle of "Maximize Learning Opportunities".

Conclusions
In this paper, ELAN 6.2 was used to conduct a comparative study of multimodal discourse in the grammar teaching of "Ba" construction by the novice teacher and the experienced teacher. Modal classification was carried out for the teaching, and levels were marked in detail. This paper investigates the categories, characteristics and differences of modalities used by the novice teacher and the experienced teacher in classroom teaching. The results show that among the four modal types, the novice teacher and the experienced teacher used more behavioral modalities. The teaching sessions were basically the same, and the modal selection of different teaching sessions was consistent between the novice teacher and the experienced teacher. Environmental modality was used throughout the teaching. However, in the grammar teaching of the experienced teacher, auditory modality is the main modality, which can create a large amount of language input for students. The experienced teacher often uses facial expressions and hand movements to guide students to learn and create learning situations. The experienced teacher was more inclined to use hand movements (indicative) to guide students' learning, which conveyed clearer and more explicit information;. The experienced teacher was also good at using appropriate modalities or multiple modalities to teach grammar in each teaching session. However, These aspects are lacking in the new teachers' teaching. Therefore, we suggest that the use of multimodality should follow the principle of optimization and minimization, create interactive classes to improve the proportion of students' discourse output, and create an immersive language learning environment for students through the use of environmental modality and appropriate facial expressions. At the same time, we suggest that focus on the diverse use of visual modality and behavioral modality to stimulate students to produce a large amount of output; in the teaching of specific grammar items, more reference should be made to the modal usage of the experienced teacher. This paper can provide some reference for novice teachers to improve their teaching of "Ba" construction and other grammar items in the future.