This volume contains a representative sample of studies presented at the 17th meeting of the Generative Approaches to Second Language Acquisition conference (GASLA-17). The chapters explore new frontiers, and make connections between second language acquisition, bilingualism, psycholinguistic methods, and computational methods. The chapters ask theoretically informed questions about the underlying grammars of language learners and bilinguals, use experimental methods to arrive at answers to those questions, and consider the value of using 'big data' to address questions in generative second language acquisition. This volume is intended for scholars and students of generative second language acquisition and related fields. It builds on prior literature by addressing the acquisition of a variety of phenomena (in syntax, semantics, pragmatics and phonology), by a variety of populations, and using a variety of data collection methods.