隨著2030雙語政策的推行，許多臺灣的英文老師也開始進行全英語教學以提升學生的英文能力，因此有關於「全英語教學」的研究也隨之增加，但其中，有關於「教師如何幫助學生理解全英語教學的課堂」和「學生對於全英語教學的課堂理解程度」的研究還有待發掘 。因此，本研究除了探討英文教師在進行全英語教學時，如何幫助學生理解課堂 內容外， 同時，也進一步探究學生對於全英語教學的看法，從中除了探討學生的「學習態度」、「學習成果」及「教學建議」外，也深入探索學生對於全英語教學的「 課堂理解程度和想法」。
本研究為一質性研究，研究對象為南臺灣一所實驗高中的 1 位高中英文教師和25位高二學生。 本研究總共為期 1 4 週 研究者 除了透過兩場的半結構式訪談以及1 4週的課室觀察，來觀察該名教師在進行全英語教學時，如何幫助學生理解英文課程外，也邀請學生填寫一份感知問卷，以了解學生對於教師全英語教學的看法。
研究結果顯示， 這位高中教師 在「單字」、「句型」、「閱讀」、「課堂活動」及「片語」五大教學內容中融入合適的教學策略，來幫助學生理解全英語教學的課堂內容；此外，大部分學生都對全英語教學的教學方式持正面看法 。最後，本研究建議高中英文老師進行全英語教學 ，以提升學生的英文能力，同時也建議高中英文老師融入合適的教學 策略，來幫助學生有效理解課程內容。

With the implementation of "the Bilingual 2030 policy,” English teachers in Taiwan have started to teach English in English to enhance students' English proficiency. Therefore, the studies related to "teaching English in English" have grown rapidly. However, little research has focused on "how EFL teachers guide students to comprehend their TEIE instruction" and "how well EFL students comprehend the TEIE instruction.”The present study is thus conducted to fill up these two gaps, to explore how EFL teachers support students' comprehension when teaching English in English and to investigate how EFL students perceive the TEIE instruction, including the aspects of "students' attitudes,"“students' learning outcome," "students' suggestion for future TEIE teaching," and“students' comprehension of the TEIE instruction and related thoughts.”
This study is a qualitative study, and the participants are one senior high school English teacher and twenty-five students. This study lasted for fourteen weeks totally. The researcher not only conducted two semi-structured interviews and fourteen-week class observations to explore how the English teacher guided students to comprehend his TEIE instruction, but she also invited the students to complete a perception questionnaire to delve into their perception of the TEIE instruction.
The results showed that the teacher applied suitable teaching strategies in each part of the TEIE teaching (e.g., vocabulary, sentence patterns, reading, class activities, and phrases) to support students' comprehension. Moreover, most of the students showed positive attitudes toward the TEIE instruction. Lastly, this study recommends that English teachers in senior high schools teach English in English to improve students' English proficiency and incorporate appropriate teaching strategies to facilitate students' comprehension effectively.

ACTFL. (2010). Use of target language in language classroom. https://www.actfl.org/resources/guiding-principles-language-learning/use-target-language-language-learning

Bernstein, B. (1990). The structuring of pedagogic discourse. Routledge.

Celce-Murcia, M. (Ed.). (2001). Teaching English as a second or foreign language. Heinle and Heinle Publishers.

Chambers, F. (1991). Promoting use of the target language in the classroom. Language Learning Journal, 4, 27-31.

Chen, G. Y. (2016). A study of the effects of English-only instruction on elementary school EFL sixth graders' English listening comprehension , [全英語教學對EFL國小六年級學生聽力理解能力影響之研究] [Unpublished master's thesis]. National Hsinchu University of Education. https://hdl.handle.net/11296/qq2zex

Creswell, J. W. (1998). Qualitative inquiry and research design: Choosing among five
traditions. Sage Publications.

Creswell, J., & Plano, C.V. (2011). Designing and conducting mixed methods research (2nd ed). Sage Publications.

Curriculum Development Council. (2017). Key learning area English language curriculum guide. www.edb.gov.hk

Denzin, N. K. (1989). Interpretive interactionism. Sage.

Dornyei, Z. (2003). Questionnaires in second language research: Construction, administration and processing. Lawrence Erlbaum Associates, Inc.

Echevarria, J. J., Vogt, M., & Short, D. J. (2017). Making content comprehensible for English learners (5th ed.). Pearson.

Elder, C. (1994). Performance testing as benchmark for foreign language teacher education. Babel: Journal of the Australian federation of modern language teachers associations. 29(2), 9-19.

Elimat, A. K., & AbuSeileek, A. F. (2014). Automatic speech recognition technology as an effective means for teaching pronunciation. JALT CALL Journal, 10(1), 21–47.

Ellis, R. (1991, April). The interaction hypothesis: A critical evaluation. Regional Language Center Seminar, Singapore. https://files.eric.ed.gov/fulltext/ED338037.pdf

Ellis, R. (1999). The study of second language acquisition. Shanghai Foreign Language Education Press.

Ellis, R. (2005). Principles of instructed language learning. System, 33(2), 209-224.

Forman, R. (2012). Six functions of bilingual EFL teacher talk: Animating, translating,
explaining, creating, prompting and dialoguing. RELC Journal, 43(2), 239–253.

Gunning, T. G. (2012). Creating literacy instruction for all children in grades pre-K to 4. (2nd ed.). Pearson.

Hartmann, P., & Blass, L. (2007). Quest: Reading and writing. McGraw-Hill.

Hayati, A. (2010). The effect of speech rate on listening comprehension of EFL learners. Creative Education, 2, 107-114.

Huang, H. L. (2019). Implementing English as a medium of instruction to promote English learning of sixth graders [Unpublished master's thesis]. National Pingtung University. https://hdl.handle.net/11296/ra25ma

Imola, K. N. (2015). Translation in ESL classes. Acta Universitatis Sapientiae, Philologica, 7(3), 87–107.

Innaci, L., & Sam, P. (2017). Using context clues as a vocabulary learning strategy: An experimental study. Journal of English language and literature (JOELL), 4(3), 39-43.

Jeon, I. J. (2008). Korean EFL teachers' beliefs of English-only instruction. English Teaching, 63(3), 205-229.

Kang, D. M. (2007). The classroom language use of a Korean elementary school EFL teacher: Another look at TETE. System, 36(2), 214-226.

Kim, S. Y. (2008). Five years of teaching English through English: Responses from teachers and prospects for learners. English Teaching, 63(1), 51-70.

Kim, K. R. (2011). Korean professor and student perceptions of the efficacy of English-medium instruction. Linguistic Research, 28(3), 711-741.

Kuo, Y. C. (2017). A study of the effects of English-only instruction on elementary students' English listening comprehension, [全英語教學對國小學生英語聽力能力影響之研究] [Unpublished master's thesis]. National University of Tainan. https://hdl.handle.net/11296/n7zm53

Krashen, S. D. (1985). The input hypothesis: Issues and implications. Longman.

Krashen, S. D., & Mason, B. (2019). A note on comprehension checking. Journal of English Language Teaching, LXI (1), 23-32.

Krashen, S. D., & Terrell, T. (1988). The natural approach. Prentice Hall.
Larsen-Freeman, D. (2000). Techniques and principles in language teaching. (2nd ed.). Oxford University Press.

Lee, K. O. (2010). Korean English teachers' perceptions of the "teaching English in English" policy [Unpublished master's thesis]. Ball State University. http://cardinalscholar.bsu.edu/bitstream/123456789/193279/1/LeeK_2010-1_BODY.pdf

Lightbrown, P. (1991). What have we here? Some observations of the influence of instruction on L2 learning. In R. Phillipson, E. Kellerman, M. S. Smith & M. Swain (Eds.). Foreign/ Second language pedagogy: A commemorative volume for Claus Faerch (pp.197-212). Multilingual Matters.

Lin, M. H. (2014). A study of the difficulties of using English in the industrial vocational senior high school English classrooms and teachers' solutions, [高工英文教師使用英語授課困難與對策之研究] [Unpublished master's thesis]. Providence University. https://hdl.handle.net/11296/pgw7e6

Lin, L. J. (2001). The study of the use of instructional languages in EFL elementary beginners' English classroom: A case study at Chiang-Tzu elementary school [Unpublished master's thesis]. National Taipei University of Education. https://hdl.handle.net/11296/4cab34.

Lincoln, Y. S., & Guba, E. G. (1985). Naturalistic inquiry. Sage.

Long, M. H. (1981). Input, interaction, and second language acquisition. Annals of the New York Academy of Sciences, 379, 259-278.

Ma, X. (2008). The skills of teacher’s questioning in English classes. International Education Studies, 1(4), 92-100.

MacMillan, J. H., & Schumacher, S. (2001). Research in Education. A Conceptual Introduction (5th ed.). Longman.

Mahmoud, A. (2014). Simplification in language learning: What do learners simplify? Studies in English Language Teaching, 2(3), 275-280.

Merriam, S. B., & Tisdell, E. J. (2016). Qualitative research: A guide to design and
implementation (4th ed.). Jossey-Bass.

Ministry of Education of the PRC. (2000). English syllabus for full-time senior high schools. http://en.moe.gov.cn.

National Development Council of Taiwan. (2018). Blueprint for developing Taiwan into a bilingual nation by 2030. https://www.ndc.gov.tw/

National Development Council of Taiwan. (2020). Highlights on implementation results of central government agencies in 2019. [PowerPoint slides]. https://www.ndc.gov.tw/

Newcomer, K. E., Hatry, H. P., & Wholey, J. S. (2015). Handbook of practical program
evaluation (4th ed.). Jossey-Bass.

Peng, C. W. (2021). An action research on using English only in English class: A case study of third graders in Nantou County, [英語課採用全英語教學之行動研究─以南投縣某國小三年級為例] [Unpublished master's thesis]. Nanhua University.
https://hdl.handle.net/11296/7gec4b

Phillippi, J., & Lauderdale, J. (2017). A guide to field notes for qualitative research: Context and conversation. Qualitative Health Research, 28(3), 381-388.

Piaget, J. (1970). Main trends in psychology. George Allen & Unwin.

Polit, D.F., & Beck, C.T. (2014). Essentials of nursing research: Appraising evidence for nursing practice (8th ed.). Lippincott Williams & Wilkins.

Rahmadani, D. (2016). Students' perception of English as a medium of instruction (EMI)in English classroom. Journal on English as a foreign language. 6(2), 131-144.

Rahman, M. S. (2016). The advantages and disadvantages of using qualitative and
quantitative approaches and methods in language "testing and assessment” research: A literature review. Journal of Education and Learning, 6(1), 102-112.

Randall, I. C. (1980). Exemplification and characterization moves in the classroom teaching of geometry concepts. Journal for Research in Mathematics Education, 11(1), 10-21.

Richards, J. (1975). Simplification: A strategy in adult L2 acquisition. Language Learning, 25,115-126.

Richards, J. C., & Rodgers, T. S. (2001). Approaches and methods in language teaching (2nd ed.). Cambridge.

Richards, J. C., & Rodgers, T. S. (2014). Approaches and methods in language teaching (3rd ed.). Cambridge.

Richards, J. C. (2017). Teaching English through English: Proficiency, Pedagogy and
Performance. RELC Journal, 2017, 1-24.

Rubin, J. (1981). The study of cognitive processes in second language learning. Applied Linguistics, 2, 117-131.

Sachdeva, A. K. (1996). Use of effective questioning to enhance the cognitive abilities of students. Journal of Cancer Educ., 11, 17-124.

Salisu, A., & Ransom, E. N. (2014). The role of modeling towards impacting quality education. International Letters of Social and Humanistic Sciences, 32, 54-61.

Shabiralyani, G., Hasan, K. S., Hamad, N., & Iqbal, N. (2015). Impact of visual aids in
enhancing the learning process case research: District Dera Ghazi Khan. Journal of
Education and Practice, 6(19), 226-233.

Shavelson, R. J. (1973). What is the basic teaching skill? Journal of Teacher Education, 14, 144-151.

Taamneh, I. M. & Al-Ghazo, A. (2021). The most common group work techniques used among the Jordanian EFL teachers when teaching English as a foreign language. Universal Journal of Educational Research, 9(1), 222-230.

Tai, F. Y. (2003). The effects of instructional language use on English achievements of senior high EFL students [Unpublished master' s thesis]. National Kaohsiung Normal University. https://hdl.handle.net/11296/s6pb7w

Terrell, T. D. (1983). The natural approach: Language acquisition in the classroom.
Cambridge University Press. The National Research Center on the Gifted and Talented. (NRC/GT) (2015). Student perceptions of school. https://nrcgt.uconn.edu/wp-content/uploads/sites/953/2015/07/sp_printversion. pdf

Tsao, Y. H. (2020). A study on English-only instruction in a second-grade class [Unpublished master’s thesis]. National Pingtung University. https://hdl.handle.net/11296/ac7yh3

Tsao, C. H. (2004). The effects of instructional languages in English class on the aspects of psychology and learning of Taiwanese vocational students, [英語課堂上所使用的教學語言對臺灣技職學生之心理及學習層面的影響]. EJEE, 6, 1-14. https://ejee.ncu.edu.tw/aboutejee

Tsukamoto, M. (2011). Students' perception of teachers' language use in an EFL classroom. Journal of Osaka Jogakuin University, 8, 143-154.

Van Pattern, B. (2003). From input to output: A teacher's guide to second language acquisition. McGraw-Hill.

Wang, F., Hwang, W. Y., Li, Y. H., Chen, P. T., & Manabe, K. (2019). Collaborative kinesthetic EFL learning with collaborative total physical response. Computer Assisted Language Learning. 32(7), 745-783.

Widdowson, H. G. (1979). Teaching language as communication. Oxford University Press.

Willis, J. (1981). Teaching English through English. Longman.

Wood, D. J., Bruner, J., & Ross, G. (1976). The role of tutoring in problem-solving. Journal of Child Psychology and Psychiatry. 17, 89-100.

Yoo, H. (2018). Historical and ideological understandings of EFL teacher education and critical policy discourse analysis of IETTP in South Korea [Unpublished doctoral dissertation]. University of Sheffield. http://etheses.whiterose.ac.uk/24358/

Young T. J. (2016). Questionnaires and surveys. In Z. Hua, Ed., Research methods in
intercultural communication: A practical guide. (pp.165-180). Wiley