Constructing explanations of scientific concepts is one of the most frequent strategies used in the science classroom and is a high-leverage teaching practice. This study analysed the explanations provided by student teachers in STEM areas from a socio-materiality perspective focused on verbal and nonverbal language and representations. The study was conducted in a hybrid research format by scholars and a preservice teacher. First, the study compared the representational elements used by 86 student teachers to construct explanations about various concepts in a roleplay setting. Next, a positioning analysis was done by a preservice teacher, to a selection of five of these explanations focused on the concept of "force". The positioning analysis highlighted the embedded voices in the construction of explanations, with a focus on the intersection between science and language. The results showed that the student teachers created explanations as static artefacts, mainly using examples, graphs and images to clarify the concepts. The voices of learners and scientists were mostly absent from the explanations, which led to the presentation of explanations in STEM areas as finished and unquestionable artefacts, with references neither to nature nor to the history of science. We reflect on the meanings attributed to learning to be a practitioner in the context of interconnecting science and language through explanations, as a process of meaning (re)production within the classroom. Implications for teacher education are discussed in order to enhance student teachers' awareness about constructing knowledge by enacting explanations in the science classroom.