This new two volume set brings together researchers from different disciplines working on the acquisition of Spanish. Volume 1 examines how children and adults acquire Spanish syntax. The first section looks at the grammar of child Spanish in both monolingual and multilingual settings. The second section investigates the nature of L2 developing grammars, with attention to the roles of the first language and of universal principles. The contributors to Volume 1 are Susana Lopez-Ornat; Maria Jose Ezeizabarrena; Jennifer Austin, Maria Blume, David Parkinson, Zelmira Nunez del Prado, and Barbara Lust; Andoni Barrena; Virginia C. Mueller Gathercole and Cecilia Montes; Juana M. Liceras, Denyse Maxwell, Biana Laguardia, Zara Fernandez, Raquel Fernandez, and Lourdes Diaz; Nora Gonzalez; Ana Teresa Perez-Leroux and William R. Glass; Joyce L.S. Bruhn de Garavito; and Silvina A. Montrul. Volume 2 is devoted to the production, processing, and comprehension of Spanish by non-native speakers. The first section examines L2 production, looking at both oral and written language. The second section investigates issues related to L2 processing and comprehension of written and oral input. The contributors to Volume 2 are James P. Lantolf; Joseph Collentine; Cristina Sanz; Manuela Gonzalez-Bueno; Jeffrey T. Reeder; Bill VanPatten; Joe Barcroft and Bill VanPatten; Tony Houston; and James F. Lee and Renato B. Rodriguez.