An important goal in early childhood science education is students' development of academic language. However, scholars disagree on whether academic language must be explicitly taught or whether it can be learned through immersive science experiences. In this case study of a co-taught second grade classroom, we use positioning theory and framings of authority of knowledge to examine teachers' and students' use of both every day and academic language. Findings suggest that inside science classrooms operating as knowledge generation environments, students can claim authority over their own knowledge and teachers are able to position students as having this authority. Findings further suggest that when teachers take the stance of negotiator within these learning environments, students can develop academic language in science through immersive experiences. This study points to the importance of early childhood teachers operating as active negotiators with students within science classrooms to meet the goal of developing their academic language knowledge and skills.