In this presentation we will first discuss the notion of mediation, which has been the object of study in an array of disciplines - philosophy, sociology, communication sciences among others. In education it has been brought to the fore by scholars who embrace the sociocultural theory (Lantolf, 2000; Lantolf & Poehner, 2014) and more broadly by all the scholars who use Vygotsky’s theories as their theoretical framework (e.g. Marginson & Dang, 2017; Schneuwly, 2008) to explain the way human beings acquire knowledge. We will then move on to discussing how it informed the new CEFR Companion Volume (Council of Europe, 2018, 2020: henceforth CEFRCV) which produced descriptors for different aspects of mediation and related areas, including plurilingual and pluricultural competence. In doing so we will present the conceptual model developed, which brings together the main facets of mediation and maps related areas onto them. Understanding the complex web of mediation in relation to languages will allow us to discuss the move away from seeing languages as static entities and what this means in terms of knowledge construction. Later we will discuss the move from the noun ‘language’ to the verb form ‘languaging’ (and related terms) that helps us capture the dynamic nature of mediation in relation to language education. This new understanding will cast light on the natural relationship between mediation and plurilingualism by connecting plurilingualism back to the different facets of mediation explained earlier in the presentation.