Learning science presents challenges for students, especially those learning in a second language. This is because second language learner students must grasp new scientific concepts while simultaneously mastering the language of instruction. Science lessons involve various linguistic demands, such as sharing observations, comparing data, and arguing with evidence. Teachers who fail to recognize the connection between knowledge and language may not provide adequate language support for additional language learners. A recent three-year research project in Copenhagen, Denmark, involved science and language teachers developing language activities for upper-primary years science lessons. In the project teachers explored the concept of semantic gravity from Legitimation Code Theory (LCT) and language activities informed by systemic functional linguistics (SFL). The project aimed to support teachers in (re)designing science units to enhance students’ science literacy and their ability to communicate scientifically. Analysis of lesson observations using semantic gravity revealed that while students were engaged and excited by practical experiments, they often had difficulty translating these experiences into generalizable scientific knowledge. In response, teachers developed activities focusing on supporting students in creating less context-dependent meanings and using more scientific language in both oral and written forms. These activities aimed to improve students’ ability to express scientific understanding, enhancing their communication of scientific ideas. This chapter includes examples of these activities, demonstrating how teachers can better support language development in science education.