The objective of this thesis is to examine how language, gestures and physical artefacts are used in science classes with emergent bilingual students who do not share the same minority language as their classmates or teachers. The purpose is to contribute to findings that can enhance emergent bilingual students’ learning in science. The data consist of classroom observations in one 3^rd grade (9–10 years old) and one 7^th grade (13–14 years old) science class. In addition, the students in the 7^th grade were interviewed. Whole-class instruction was carried out monolingually in Swedish. The students typically made meaning of the activities without any language limitations during conversations following an initiation, response and evaluation pattern (IRE). However, during longer conversations the students’ language repertoire in Swedish frequently limited their possibilities to express themselves. During group-work activities, students with the same minority language worked together and used both of their languages. One strategy used among the students to overcome language limitations was translating unfamiliar words into their minority language. In general, this supported the students’ learning in science. Occasionally, the students made incorrect translations of scientific concepts. The interviews with the students demonstrated how monolingual exams may limit emergent bilingual students’ achievements in science. When students’ language proficiency limited their possibility to express themselves, the students showed what they meant by using gestures. This resulted in the continuation of the lessons as both other students and teachers drew on the used gestures to talk about the science content. The physical artefacts implied that the students experienced the science content by actually seeing it, which the teacher then drew on to introduce how the phenomena or process in question could be expressed in scientific language. When students’ proficiency in the language of instruction limited their possibilities to make meaning, using physical artefacts enabled them to experience unfamiliar words being related to the science content and learn what they mean.