Online teaching and learning have become widespread with the emergence of the Internet and other new technologies. However, online environments pose new challenges to those seeking to develop or choose suitable teaching approaches, and this is especially true in the case of language courses. Using survey and interview data, this study examines online language teachers' teaching practices, their adjustments toward online teaching, and the professional development (PD) that they received and expected to receive in a virtual high school in the United States. The findings suggest that online teachers generally used more non-content-related teaching practices than content-related teaching practices in online language courses; and that instructors in Chinese -- the only language course that offered weekly synchronous sessions -- exhibited more frequent use of content-related teaching practices than teachers of other world languages. The study also sheds light on teachers' adjustment to the online environment, which impacts their management, social, and pedagogical roles. Lastly, our analysis of the PD that teachers felt they needed, as against what they actually received, underscores the need for more PD in the areas of online-course design and content-related technology integration. The results of this study could be useful to online language teachers and researchers, and point the way to improvements in teacher education vis-à-vis online language teaching.