Introduction Evangelia Adamou and Yaron Matras Part 1. Methods and theoretical approaches 1) Processing multilingual dataBarbara E. Bullock, Almeida Jacqueline Toribio, Jacqueline Serigos, and Gualberto A. Guzman 2) Language contact in the labPaola E. Dussias, Judith F. Kroll, Melinda Fricke, and Michael A. Johns 3) A variationist perspective on language contactShana Poplack 4) The 4-M model: different routes in production for different morphemesJanice L. Jake and Carol Myers-Scotton 5) Theoretical approaches to the grammar of codeswitchingJeff MacSwan 6) Usage-based approaches Ad Backus Part 2. Processes and dimensions 7) Social factorsKofi Yakpo 8) Language contact: pragmatic factorsPeter Auer 9) Cognitive factors of language contactKees de Bot and Lars Bulow 10) Typological factorsFelicity Meakins 11) Cross-language contact in the developing grammars of bilingual childrenJennifer Austin 12) First language attrition in the twenty-first century: How continued L1 contact in the digital age fuels language attrition theorizingMerel Keijzer Part 3. Outcomes 13) Borrowing Yaron Matras and Evangelia Adamou 14) Codeswitching and bilinguals’ grammars Rena Torres Cacoullos and Catherine E. Travis 15) Convergence Björn Wiemer 16) Creoles and pidgins: why the latter are not the ancestors of the formerSalikoko S. Mufwene 17) Mixed LanguagesCarmel O’Shannessy 18) Linguistic landscape and urban multilingualismCarla Bagna, Monica Barni, and Martina Bellinzona 19) Urban youth speech styles in multilingual settingsMargreet Dorleijn, Maarten Kossmann, and Jacomine Nortier Part 4. Linguistic areas20) The BalkansVictor A. Friedman 21) AnatoliaAnaïd Donabedian and Ioanna Sitaridou 22) Language contact in the Asian regionUmberto Ansaldo and Lisa Lim 23) Eastern PolynesiaMary Walworth 24) Linguistic MelanesiaAntoinette Schapper 25) Language contact in North AmericaMarianne Mithun 26) Language contact in West AfricaFriederike Lüpke and Rachel Watson