Over the past decade, there has been an increasing interest in research on teacher knowledge about technology integration, namely Technological Pedagogical Content Knowledge (TPACK). However, few studies have investigated how teachers transform their teaching with technology. To fill this gap, the present study adopted the Substitution, Augmentation, Modification, and Redefinition (SAMR) model to investigate the degree to which four Taiwanese English as a Foreign Language (EFL) teachers enacted their TPACK in the context of teaching English with iPads, as well as identified contextual factors that might influence the levels of their TPACK enactments. Results suggested that, although some of the teachers' iPad-based teaching indicated their competency in transforming their teaching, their teaching was predominantly enhanced by the tablets as a substitute to deliver linguistic input to their students in conventional teacher-centred classrooms. In addition, students' access to iPads and a wireless network was considered essential. This technological problem might constrain the teachers from enacting TPACK towards the higher levels of the SAMR scale. This study contributes to the literature on TPACK by providing empirical evidence on investigating the levels of TPACK enactments using the SAMR model. [For the complete volume, "Professional Development in CALL: A Selection of Papers," see ED593926.]