教师话语分析一直以来都是教育领域的重要研究课题。随着现代技术的迅速发展，传统的单一语言模态逐渐被多模态形式所取代。在课堂教学中，教师运用多模态话语已成为主流。传统的教师话语分析与教师话语的本质相冲突，需要新的研究范式来克服现有的局限性。多模态话语分析作为一种分析教师话语的新范式，受到了研究者的广泛关注。然而，有关动态教学视频中的模态前景化和模态关系的研究较少。因此，本文以五节高中英语示范性阅读课和三节线下课为基础，深入探讨了英语课堂中的模态前景化、模态关系和模态意义建构。本文以多模态文体学为理论基础，旨在总结高中英语教师使用模态的特点和规律。

研究发现，在模态前景化方面，口语和文字标注数量较多，作为听觉和视觉信息传递的主要模态，始终占据前景。图片可以作为背景元素来强化其他模态，也可以作为前景化模态，而可视化工具则用于构建教学内容，始终处于前景。音乐和音效作为视频中的背景元素。姿势模态，包括凝视、社交距离和手势，主要占据背景，用于突出其他模态。

在模态关系方面，模态关系可以为两种主要类型：互补关系和非互补关系。互补关系通常是以人声为主要模态，以图像、文字和姿势模态进行辅助和补充。最常见的互补关系存在于口语和姿势模态之间。在非互补关系中，最常出现的冗余关系表现为文字和人声之间的重复。在英语阅读课堂中，单一模态情况不存在。在设计英语课堂时，模态应相互补充以传达意义，实现最佳交际效果。

关于模态意义的构建，模态构建的意义数量从高到低依次为互动意义、再现意义和构图意义。在互动意义方面，教师利用各种模态影响学生对学习材料和教师本人的态度。教师通过凝视和手势与学生建立联系，寻求认可并引导学生注意。教师与学生之间的不同距离反映出不同的关系，通常保持平视交流以示平等。在再现意义方面，教师通过眼神和手势将学生与幻灯片上的图像或文字连接起来，展示教学内容的传递。幻灯片上图像的选择和设计反映了教学内容的整体和部分关系。教师的象征性手势为学生提供了符号性暗示，加强了语言内容的传递。在构图意义方面，教师以合适的方式安排教学内容，突出关键信息并清晰传达信息。利用不同的字体，如颜色、大小和斜体来强调关键信息，同时采用抽象到具体的组织和隔离信息的方式来排列视觉元素。

本研究为英语课堂教学中教师的模态使用提供了如下建议。第一，教师应该充分考虑模态前景化的选择，以最大限度地发挥模态的表达功能。第二，在设计模态关系时，教师应确保组合符合积极性原则。模式应相互补充，避免矛盾或冲突。第三，在观察和学习其他教师的课程时，教师可以从多模态使用的角度来评价课堂。

The analysis of teacher discourse has been a significant research focus in education. As modern technology rapidly advances, traditional single linguistic forms have been supplanted by multimodal expressions. In the context of English lessons, the adoption of multimodal discourse by teachers has become widespread. Consequently, traditional approaches to analyzing teacher discourse are at odds with the essence of multimodal discourse, necessitating novel research paradigms to overcome existing constraints. Multimodal discourse analysis, as a new paradigm for analyzing teachers’ discourse has received extensive attention from researchers. However, there remains a dearth of detailed analysis of modal foregrounding and modal relationships in dynamic teaching videos. Therefore, this thesis delves into modal foregrounding, modal relationships, and the construction of modal meaning in English lessons based on five exemplary high school English reading lessons and three offline lessons. Drawing upon multimodal stylistic, this thesis aims to summarize the characteristics and patterns of the modalities used by high school English teachers.

The thesis reveals that oral language and texts annotations are prevalent in modal foregrounding, serving as primary modalities for auditory and visual information transmission, consistently occupying the foreground. Pictures can serve as background elements to reinforce other modalities or as foregrounded modalities, while visualization tools structure teaching content and remain foregrounded. Music and sound effects serve as background elements to emphasize visual content in videos. Posture modalities, including gazes, social distances, and gestures, predominantly occupy the background, highlighting other modalities.

Modal relationships are categorized into two main types: complementary relationship and non-complementary relationship. Complementary relationship typically involves oral language as the primary modality, with images, texts, and posture modalities reinforcing and complementing it. The most common complementary relationship is between oral language and posture modalities. As for non-complementary relationship, redundant relationship with the highest frequency of occurrence often exhibit between texts and oral language. Single-modal situations are nonexistent in English reading classrooms. When designing English lessons, modalities should complement each other to convey meaning effectively.

In terms of modal meaning construction, the number from high to low is interactive meaning, representational meaning, compositional meaning. As for interactive meaning, teachers utilize various modalities to influence students’ attitudes toward learning materials and themselves. They establish contact with students through gazes and gestures, seeking acknowledgment and guiding student attention. Different distances between teachers and students reflect different relationships, typically maintaining eye-level contact to demonstrate equality. In terms of representational meaning, teachers connected students with images or texts on PPT using gazes and gestures, demonstrating the transmission of teaching content. The selection and design of images on PPT slides reflect overall and partial relationships within teaching content. Iconic gestures by teachers provide symbolic cues to students, reinforcing the transmission of language content. As for compositional meaning, teachers arranged teaching content in appropriate ways to highlight key information and deliver messages. Formatting techniques such as color, size, and italics emphasize key information, while abstract-to-concrete organization and various isolation techniques arrange visual elements.

This thesis provides the following recommendations for teachers’ modal usage in English classroom. Firstly, teachers should thoroughly consider the selection of foregrounded modalities to maximize their expressive function. Secondly, when designing modal relationships, teachers should ensure that the combinations adhere to the principle of positivity. Modalities should complement each other, avoiding contradictions or conflicts. Lastly, when observing and learning from other teachers’ lessons, teachers can evaluate the classroom from the perspective of multimodal discourse.