In order to enhance students' proficiency in the academic language, building up more formal language on the basis of individual and everyday language is claimed as a fruitful approach. However, there is little empirical research on how students adopt and develop lexical means of the academic language. This paper addresses this field of research for the case of concept-specific lexical means for relative frequencies by presenting the applied design principles for learning opportunities as well as empirical insights into initiated concept-and language development processes.