Educators can use digital tools to meet emergent bilingual students’ unique needs (e.g., Andrei, 2017; Liu, Navarrete, & Wivagg, 2014; Lund, 2008). However, language teachers generally feel unprepared to use technology with students even though many use digital tools in their daily lives (e.g., Dooly, 2009; Kessler, 2006). Research can further examine how to prepare teachers to leverage technology to support emergent bilingual learners. In this study, I used ethnographic methods to explore six pre-service teachers’ (PSTs) experiences learning about and using digital tools in ways intended to support emergent bilingual students. I interviewed the PSTs and observed their participation across student teaching and a concurrent practicum course. I analyzed these data through the lens of cultural-historical activity theory (Engeström, 2001; Yamagata-Lynch, 2010) to examine how PSTs navigated dynamic, interacting activity systems. I also drew on polyfocality to conceptualize learners’ attention on multiple physical and virtual resources during interactions. Findings revealed that the PSTs’ participation in teacher education was characterized by a shared responsibility where all the PSTs, their teacher educator, and mentor teachers contributed new digital tools and polyfocally co-constructed knowledge about the possibilities for classroom technology implementation. The shared responsibility and polyfocal co-construction of knowledge afforded the PSTs opportunities to learn in the moment, and many described their learning as “playing around.” It also afforded PSTs opportunities to reflect on their future practice and evaluate new technologies. Within student teaching, the PSTs sanctioned specific digital tools, but their emergent bilingual students deliberately made choices about technologies that would support their learning about self-chosen topics. Because of the ever-evolving nature of educational technology and students’ complex uses of multiple digital tools simultaneously, teachers must be prepared to continually explore new technologies, critically analyze their benefits, and use them in ways that afford their emergent bilingual students opportunities to make independent choices.