Many multilinguals in Europe habitually use the linguistic strategies often attributed to users of English as a lingua franca (ELF). ELF, in which native speaker norms are not invoked, may be the perfect arena for multilinguals to exploit what Vivian Cook calls "multicompetence", a dynamic multilingual system in which more than one language can be activated at the same time. What might be considered, in the use of a native language, and from an SLA perspective, as accidental transfer lapses, erroneous words, deviant idioms and collocations and unconscious calques, can equally be seen as signs of linguistic awareness and enhanced communicative competence when used in ELF. Many Europeans can understand a large amount of cognate lexis from different languages, making borrowing and code-switching viable strategies even where interlocutors do not share the same languages, especially when speaking English, a Germanic language with a huge amount of Latinate and French lexis. This article considers the potential and the limitations of language mixing by speakers of ELF. Allan James has suggested that European ELF may be a kind of performance without competence, but it might equally be seen as a widespread instantiation of multicompetence in action. (Contains 33 notes.)