Introduction Julia Herschensohn and Martha Young-Scholten; Part I. Theory and Practice: 1. Theories of language from a critical perspective Jan Koster; 2. History of the study of L2 acquisition Margaret Thomas; 3. Theoretical approaches Florence Myles; 4. Scope and research methodologies Melinda Whong and Clare Wright; Part II. Internal Ingredients: 5. The role of the native language Claire Foley and Suzanne Flynn; 6. Learning mechanisms and automatization Richard Towell; 7. Generative approaches and the poverty of the stimulus Bonnie D. Schwartz and Rex A. Sprouse; 8. Learner internal psychological factors Jean-Marc Dewaele; 9. Alphabetic literacy and adult L2 acquisition Elaine Tarone, Kit Hansen and Martha Bigelow; Part III. External Ingredients: 10. Negotiated input and output interaction María del Pilar García Mayo and Eva Alcón Soler; 11. Second language identity construction Elizabeth Miller and Ryuko Kubota; 12. Socialization Daniel Véronique; 13. Variation Vera Regan; 14. Electronic interaction resources Astrid Ensslin and Cedric Krummes; Part IV. Biological Factors: 15. Age related effects Julia Herschensohn; 16. Childhood L2 acquisition Belma Haznedar and Elena Gavruseva; 17. Incomplete L1 acquisition Silvina Montrul; 18. Third language acquisition Jason Rothman, Jennifer Cabrelli Amaro and Kees de Bot; 19. Language processing Alice Foucart and Cheryl Frenck-Mestre; 20. Affect and the brain Andrea Mates and Anna Joaquin; Part V. Properties of Interlanguage Systems: 21. The lexicon James Milton and Giovanna Donzelli; 22. Semantics Laurent Dekydtspotter; 23. Discourse and pragmatics Roumyana Slabakova; 24. Morphosyntax Tania Ionin; 25. Phonology and speech Ellen Broselow and Yoonjung Kang; Part VI. Models of Development: 26. Explaining change in transition grammars Michael Sharwood Smith, John Truscott and Roger Hawkins; 27. Stage-like development and organic grammar Anne Vainikka and Martha Young-Scholten; 28. Emergentism, connectionism and complexity models Randal Holme; 29. Input, input processing and focus on form Joe Barcroft and Wynne Wong; 30. Sociocultural theory and the zone of proximal development Amy Snyder Ohta; 31. Nativelike and non-nativelike attainment Donna Lardiere.