Obviously the title is not "swimming and sinking", which intends to adress the question whether these terms should be used as a pair in the understanding of a scientific concept. As neither the terms themselves, nor the underlying linguistic or technical concepts are on the same level, 'swimming' conceptually, linguistically and technically evokes a different understanding than 'sinking'. The parallel understanding of subject matter as well as the appropriate use of language is an essential feature of learning (in science education) (Leisen 2015). In particular, the technical understanding of the children is only successful if they can express an understanding of the technical content in everyday language, otherwise technical language remains empty of content (ibid.). The results of a literature review study are presented. The research focuses the didactic und technical basis for a conceptual development of the subject “swimming” including suggestions regarding empirical tests in the future. Subjects must therefore be developed consistently in everyday language and technical language in order to allow for a technical understanding (Quehl & Trapp 2013; Fürstenau & Lange 2010).