The increase in the use of educational technologies in Australian high schools has sparked this investigation into how Year 9 (13 to 14 years of age) students experience and negotiate a new technology enhanced learning environment in a bilingual classroom setting. The paper is about examining the students' language practices in German and English while using a Managed Learning Environment (MLE). The study aims to unearth how such translanguaging practices (using both German and English to communicate in bilingual education settings) contribute to and shape self-regulated learning in a scientific open inquiry process. This is corroborated by insights into student reflections on using the MLE in two languages, with data gained from a student survey. The study further analyses the relationship between bilingual language practices and adaptive tool use. The effectiveness of online learning environments depends on the students' adaptive tool-use (Barzilai & Zohar, 2006; Lust, Vandewaetere, Elen, & Clarebout, 2014) and the ability to engage in self-regulatory learning practices (Zimmerman, Bembenutty, & Schunk, 2013). Data were collected via voice recordings, a student-designed questionnaire and focus group interviews with 22 Year 9 students covering 18 Biology lessons during 6 weeks, over two consecutive years. The study revealed that students' self-regulatory practices during open inquiry processes developed in specific ways through the exposure to a bilingual classroom setting, e.g. by being exposed to unknown terms in German which led them to search for translations and then on to further self-initiated and self-regulated research to find explanations online However, when biology content knowledge was pre-prepared (in the second language of German) by the teacher in guided customized simulations on a computer software tool, students seem to favor such guided practices over self-initiated and self-regulated research as shown during the open inquiry task. However, independent of the specifics of bilingual language use in open or guided inquiry, the tool-use also appeared to be reliant on students' prior disposition. Consequently, results of this study might have interesting implications for the future customization of online learning spaces for high school students and educators in bilingual settings as well as other fields. [For full proceedings, see ED571332.]