The concluding chapter summarizes the results and emphasizes the impact of the findings on future heritage language research and studies on bilingualism and language change in general: It stresses the necessity of including grammatical and pragmatic contact phenomena and discusses the importance of the interplay of extralinguistic factors and various types of linguistic developments: acquisition context, impact of schooling and literacy, contact with different registers and speakers. It explains individual processes in heritage language speakers, such as entrenchment processes, co-active activation of languages in the bilingual brain, as well as language awareness and metalinguistic knowledge. In addition, the role of normativity in diaspora communities, the challenge of relic varieties and the role of Standard German as language of schooling are discussed. Moreover, the chapter includes general observations on language maintenance in German heritage communities. It emphasizes the implications for future research: implications for the development of the German language in general, implications for the theory of language contact and implications for heritage language research.