The contributions in this volume focus on methodological and theoretical issues in linguistic fields where Norbert Dittmar has worked throughout his academic career. Methodological and corpus linguistic questions are discussed; in sociolinguistics, the spectrum ranges from personal ads in the GDR to 'Turkish German' and the migration situation in Italy. Issues of language use and description cover topics from deixis to human-machine interaction. Central themes from second language acquisition research, such as vocabulary acquisition, word order, finiteness, interrogation, topic, or actionality, as well as findings related to the age factor, are discussed, with particular attention given to the acquisition of German as a second and foreign language alongside the acquisition of other European languages.