This article originates in the premise that interesting and useful information about Teaching English as a Foreign Language may not be well-known in Japan simply because it is not written in either English or Japanese. One such case is the pedagogical concept of cross-language mediation, which typically necessitates informal interpreting and translating. Drawing on the writings of German and Greek academics, the author outlines the meaning of this concept, what kind of pedagogical tasks it involves, and how it can be related to assessment.