English as a lingua franca (ELF) is a means of communication in English between speakers who have different first languages. While some definitions (e.g. House, 2003) exclude native speakers of English (NSs) from ELF interactions, others allow NSs to take part in ELF interactions as long as they defer to ELF norms (Jenkins, 2009b). In order for an interaction to be classified as ELF, however, NS contributions are always expected to be minimal (Jenkins, 2009b: 41). ELF is therefore mainly, if not exclusively, used between non-native speakers of English (NNSs).