Based on corpus data and the results of a linguistic survey, we will examine grammatical and lexical developments in two relatively new varieties of Modern German: Kiezdeutsch and Namdeutsch. Both varieties are spoken in multilingual speech communities in Germany and Namibia respectively. In spite of considerable differences in the contact languages involved, the social backgrounds of the speakers and other differences, our comparison shows that the inovations have a series of conspicuous similarities. For example, gibs has developed into an element similar to a particle indicating existance and so functions as a focus marker. New particles are also being borrowed. Furthermore, in the course of a semantic-pragmatic development, the article in (ein) bisschen or bietje/bikkie has been gradually disappearing. In comparison to the German spoken in monolingual contexts, the relatively strong changes in Kiezdeutsch and Namdeutsch bear witness to the highly innovative power of these varieties. In addition, the parallelism of the developments in the domains studied here indicates fundamental tendencies of the internal structure of German.