本研究主旨在探討教師在不同層級的兒童英語教室所具有語言的特徵。文中從二個角度來分析教師語言：句法及言談功能。藉著分析教師語言的形式及功能，期能暸解教師語言的內涵，幫助學生語言學習。 有三位兒童英語老師及三個不同層級的班級參與本研究,分別為初級，中級及高級。每位教師分別接受四節課之錄音，每一個層級選擇錄音最清晰的二節課予以轉成文字稿。經仔細檢視文稿後，每一層級選擇十五分鐘之語料做分析比較。以二項句法特徵及十一項言談功能來分析，記出其頻率，算出百分比及相關的統計方法。本研究的主要發現如下： (1) 教師語言平均語句的長度隨著層級愈高而增加。教師在初級的兒童 英語教室之平均句長為2.95，在中級教室為3.47，在高級教室為4.53。此顯示，教師隨著學生程度的增加而調整其語句長度。 (2) 教師語言的語法正確率在三個層級都很高。教師在初級教室的語法正確率最高為99.52%，其次為中級教室96.20%，最低為高級教室為94.21%。此顯示，教師給予學生相當正確的語言輸入(Input)。 (3) 教師語言的言談功能隨著層級的增加而不同。在十一項言談功能中，初級教室教師最常用的是練習(Drill)，中級教室教師最常用的功能是講解(Informative)，而高級教室教師用的最多的是發問(Elicitation)。 本研究亦提據結果提供以下的教學建議：教師應依學生程度的不同，調整其言談功能，同時教師需提供學生更多語言溝通的機會，培養學生語言溝通的能力。 / This study aims to investigate the characteristics of teacher talk in child EFL classrooms of different levels. Teacher talk is analyzed from two perspectives：syntactic and discourse. Three child language teachers and three classes of different levels participate in this study: the elementary, intermediate and advanced levels. Four units of each level are recorded. After initial screening, two units of each level are transcribed on the basis of intelligibility. By careful examination, only a portion lasting about ten to fifteen minutes at each level is selected for data analysis. Two formal characteristics--MLU (mean length of utterance) and grammaticality--are measured in syntactic analysis; and in discourse analysis, the function of teacher talk is analyzed. For syntactic analysis, teachers' MLU is counted; the grammaticality of teachers’speech is measured in the proportion of correct utterances to the total amount of utterances. For discourse analysis, teachers’utterances are categorized according to a discourse model adopted from Tsui (1985). Three major findings are found in this study. Firstly, teachers’ MLU increases as students’ proficiency increases. Teacher’ MLU at the elementary level is 2.95, at the intermediate level 3.47 and at the advanced level 4.53. It shows that teachers adjust their length of utterances to the proficiency level of students. Secondly, the grammaticality of teachers’ speech is very high in all the three classrooms. The grammaticality is 99.52% at the elementary level, 96.20% at the intermediate level and 94.21% at the advanced level. It shows that teachers provide students a very correct target language input. Thirdly, the functions of teacher talk are different at different levels. Among eleven functions, teachers use the function “Drill” most frequently in the elementary classroom, “Informative” in the intermediate classroom and“ Elicitation” in the advanced classroom. Two factors may be attributed as the cause the differences of teachers’ functions：the learners’ stage of development and the teaching method. Pedagogical implications are suggested according to the findings. Teachers are suggested to speak in such a way as to provide students with opportunities to speak in the target language if the purpose of teaching is to develop communicative ability.

當母語者與非母語者在進行溝通時，母語者通常會使用較為簡化的語言形式，此種語言形式研究者稱之為「調整語」。本文旨在探討在台灣的成人美語教室中，外籍教師針對不同程度的學生，使用調整語的情形，文中主要從「句法」與「言談功能」兩個角度分析外籍教師的語言使用。 有三位教授中、高級美語會話的外籍教師參與本研究，每位教師於不同層級的課堂各接受兩次錄音，總計收集到18小時的錄音語料，351頁的逐字稿，全數經過分析比較後，主要發現如下： (1) 外籍教師之語言平均句長並未隨著學生程度越高而有顯著增加。外籍教師在中級教室之平均句長為8.197，在高級教室為8.388，p>0.05。此結果顯示，當學生程度到達中級以上，「句長上的調整」似乎不再是外籍教師採用的調整方式。 (2) 外籍教師之語法正確率在兩個層級都非常高。外籍教師在中級教室之語法正確率為99.81%，在高級教室為99.79%，在兩個層級都僅有10個錯誤句子，透過錯誤類型分析，發現中級教室中出現較多句法層面上的錯誤，而篇章層面的錯誤則全出現在高級教室中。 (3) 外籍教師之言談功能會隨學生層級不同而有調整。外籍教師在中級教室中給予較多主動的語言輸入、提供較多的發問，主要功能為傳輸語言知識；在高級教室中，教師減低發言的比例，使用較多的回饋功能。 綜合以上研究結果發現，英語為母語之外籍教師在上課時面臨不同語言程度的非母語對話者有不同的語言調整方式，在中、高級程度的班級上，「句法上的調整」不再是外籍教師的主要考量，而轉向採用「語言功能上的調整」，在教學應用上，儘管隨著學生層級的增加，外籍教師減少了「主動語言輸入」功能，而採用較多的「語言回饋」功能，但整體而言，學生發言的比例仍然偏低（中級教室9.93%；高級教室12.15%），教師應給予學生更多的口語練習機會，採用更多的回饋機制，以增加學生之溝通能力。 / When addressing to non-native speaker, native speakers will modify his speech to what he thinks is simpler and easier for the non-native listener to comprehend. Such simplified register is referred to as “Foreigner Talk.” The present study aims to explore both the syntactic and discourse characteristics of FT in Taiwan’s adult English classrooms. Three measurements (1) syntactic complexity (2) grammaticality and (3) discourse functions are adopted to investigate if the interlocutor’s language proficiency affects the foreigner teacher’s language use. The data were collected from 18-hour recording of three English native speakers’ utterances in intermediate and advanced classrooms. The major findings of this study are summarized as follows: (1) In terms of syntactic complexity, the mean words per t-unit at both levels are very similar with 8.197 at the intermediate level, and 8.388 at the advanced level. The result of t-test (p>0.05) also indicates that no significant difference is found concerning the language complexity between the two levels. It is suggested that the adjustment of language complexity may only resort to students with lower proficiency. Once the student’s proficiency goes beyond a specific level, the length of teacher’s utterances will keep in a fixed range. (2) In terms of grammaticality, over 99.79% of the foreigners’ utterances are grammatical sentences in both language classrooms, showing that the foreigners’ language form is quite accurate. By analyzing the 20 ungrammatical utterances, it reveals that the foreigner teachers are more likely to utilize the syntactic adjustment for the lower level learners and conserve the discourse adjustment for the more advanced ones. (3) In terms of discourse functions, Sinclair and Coulthard’s model (1992) is modified to categorize the functions of the foreigners’ utterances. It is found that the distribution of the functions varies with the development of the students’ language ability. The foreigner teachers use significantly more initiation functions to the intermediate students and provide much more responsive functions for the advanced students. Based on the findings of this study, some pedagogical implications are addressed. It is suggested that teachers should pay more attention to their language use and consider if their adjustments of language really enhance language learning. In order to increase the learning potential, teachers are recommended to employ more judicious silence, to reduce the percentage of teacher-initiated utterances and to resist the temptation to interrupt. Also, teachers should realize that they are not only an instructor but also an interlocutor for their students at the same time. By realizing the dual roles as being a language teacher, the teacher can make language class less artificial and help learners to overcome the gap between communication in and outside the classroom.