Book excerpt: This volume provides new insights into various issues on prosody in contact situations, contact referring here to the L2 acquisition process as well as to situations where two language systems may co-exist. A wide array of phenomena are dealt with (prosodic description of linguistic systems in contact situations, analysis of prosodic changes, language development processes, etc.), and the results obtained may give an indication of what is more or less stable in phonological and prosodic systems. In addition, the selected papers clearly show how languages may have influenced or may have been influenced by other language varieties (in multilingual situations where different languages are in constant contact with one another, but also in the process of L2 acquisition). Unlike previous volumes on related topics, which focus in general either on L2 acquisition or on the description and analyses of different varieties of a given language, this volume considers both topics in parallel, allowing comparison and discussion of the results, which may shed new light on more far-reaching theoretical questions such as the role of markedness in prosody and the causes of prosodic changes.