In this paper, we discuss the results of a case study about the teaching strategies used by three primary school educators to decode Grade 4 science terminology. In South Africa, the study of science is formally introduced to learners in Grade 4. Additionally, Grade 4 is the year when learners transition from being taught in their native languages in Grades 1 to 3 to being taught in English. This presents the challenge of learning a new subject in an unfamiliar language. Research shows that the majority of South African primary school learners find science terminology difficult to comprehend due to linguistic challenges, which could account for their poor performance in science assessments. The way educators decode science terminology during science lessons could affect learners' comprehension of science vocabulary and consequently their performance in science. Semi-structured interviews were used to collect data in a qualitative case study in order to determine the strategies used by three science educators to teach and decode science terminology in Grade 4. The study findings suggest that the participating educators use ad hoc, teacher-centered teaching strategies to decode science concepts. These findings have implications for the preparation of primary school science educators in teacher training institutions.