The terms "plurilingualism" and "multilingualism" are generally used synonymously. However, it is possible to distinguish between them. The Council of Europe does so in its Common European Framework of Reference for Languages, although the difference between the two concepts remains unclear (CoE 2007 [2001]: 12). In short, multilingualism refers to groups of people, language communities and organizations and implies the use of more than one language within them, while plurilingualism describes the knowledge of more than one language in a single individual, focusing on the relationship between the different languages in their own linguistic repertoire (cf. Berthele 2010).

This “Scientific Café” talk builds on these definitions and discusses their terminological distinction from a linguistic diversity perspective. As the examples of countries such as Canada and Luxembourg show, it appears essential that educational policies focus on a generalized expansion of the individual plurilingual repertoire in order to strengthen linguistic diversity. Accordingly, social structures that are “only” multilingual need to become plurilingual, and plurilingual competencies are to be valued within institutions and organizations at different levels. We hope that this presentation will raise awareness among an Esperantist audience — that is probably already largely sensitive to issues of language equality and policy — of the importance of distinguishing between plurilingualism and multilingualism and of the role of such a distinction in strengthening linguistic diversity on a global scale.