The paper outlines the main principles of grammaticalization, the Code-Copying Model, and the emergence of isomorphic structures in language contact. It offers a number of examples of code-copying and grammaticalization, and a summary of the author’s approach to contact-induced change and grammaticalization. In particular, it argues that grammaticalization – in the usual sense of a process by which lexical items lose some or all of their lexical meaning and become grammatical markers – cannot be shared by codes as a result of code-copying. At the same time, it contends that shared grammaticalization in the sense of a parallel development of elements is clearly possible.