trilingualism, multilingualism and tertiary language learning have been around for a long time, but they were not recognized as special cases of language acquisition and language competence. Only recently have researchers begun to check out what distinguishes third and fourth language learning/acquisition from second language learning/acquisition and to search for differences and common features in bilingualism and tri-/multilingualism. Around the globe, researchers are working in areas like sociolinguistics, psycholinguistics and educational linguistics in order to determine the scope of trilingualism and related areas. We were fascinated to see the broad variety of research questions, topics, methods, and languages under investigat...