The concept of "English only" as the best teaching-learning method in English as a foreign language classrooms has been promoted in Taiwan over the last decade. During that time, the concept has been queried and debated. Teachers and learners have come to realise that for beginners and slow language learners, the use of codeswitching in the classroom is both inevitable and necessary. This study examines the use of codeswitching in two freshman English classrooms in a university in southern Taiwan. The two primary aims of this study are: to explore the nature of classroom talk, focussing specifically on how teachers and learners use more than one language to talk around monolingual textbooks and thereby successfully accomplish lessons; and secondly to investigate the conflict and accommodation in the use of languages between teachers and learners in English classrooms. This microethnographic study utilised in-class observations, together with field notes and audio recordings. Additionally, three sets of group interviews were conducted at the end of the semester. The study has found that in order to arouse students' interest in learning English, teachers often choose to switch between English and Mandarin in classrooms. Even though many participants have expressed the view that using English only is the ideal teaching and learning method, the teachers commonly choose to switch codes to unlock the meanings from the monolingual English textbooks, for classroom management and to promote harmony in the classrooms. Students, too, were allowed to use Mandarin and Taiwanese in the classrooms.