This volume presents sixteen new articles on the acquisition of Romance languages by both well-established researchers and vital new contributors to the field. Under a generative umbrella, the articles in this collection investigate the acquisition of French, Romanian, Spanish, Catalan, Italian and Portuguese across different contexts including first language acquisition, bilingual acquisition, specifically impaired first language acquisition, child L2 acquisition, second language acquisition, as well as first language attrition. This volume advances our understanding of how languages are acquired and how the study of Romance languages contributes to clarifying challenging open questions on the acquisition of key functional categories and other related phenomena. In particular, the articles included assess complexity as a relevant factor shaping children’s acquisition of syntactic and phonological structures, they refine crucial theoretical constructs such as parameter setting and language transfer, and propose language change as another crucial factor affecting the process of language acquisition and attrition.