Via a multi-domain, multi-response classroom observation instrument, we observed and analyzed treatment and control teachers' pedagogical differences when applying cooperative, collaborative, and peer-tutoring (CCP) strategies in Grade 1 bilingual classrooms with English learners (ELs). We found that with the support of ongoing, structured, and curriculum-aligned virtual professional development (VPD), treatment teachers allocated more time in engaging ELs via CCP strategies and evaluating and providing feedback to ELs. Moreover, treatment ELs had more opportunities to be involved in CCP activities that promoted dense cognitive, academic English language development.