The volume presents new insights into two basic theoretical issues hotly debated in recent work on grammaticalization and language contact: grammatical replication and grammatical borrowability. The key issues are: How can grammatical replication be distinguished from other, superficially similar processes of contact-induced linguistic change, and under what conditions does it take place? Are there grammatical morphemes or constructions that are more easily borrowed than others, and how can language contact account for areal biases in the borrowing (vs. calquing) of grammatical formatives? The book is a major contribution to the ongoing theoretical discussion concerning the relationship between grammaticalization and language contact on a broad empirical basis.