This chapter focuses on typical language contact phenomena of German as a heritage language in the area of lexical and phrasal units as well as idiomatic constructions. The first part addresses lexical borrowing, i.e. the transference of form–meaning pairs and explains motivations for lexical borrowing and its typical domains in German heritage communities. The second part deals with the transference of meanings in lexical-based constructions, generally referred to as semantic borrowing. Following the categorization of Haugen, it discusses different types of meaning transference such as homologous, synonymous and homophonous extensions which are illustrated by examples from different German heritage communities. A special focus is on the formation of new form-meaning pairs in lexicalized constructions (e.g. light verb constructions and idiomatic phrases). In a concluding section, the psycholinguistic explanations for semantic restructuring processes and the formation of new constructions are discussed by presenting a model that explains the connection of lemmas in the mental lexicon. Furthermore, the emergence of new construction types through the process of interactive activation in speech production is illustrated and speakers’ agency and awareness of transference processes are discussed.