AbstractThis article presents a review of current research in experimental syntax, with a focus on three open questions and the (methodo)logical tools that have been developed to explore them. The three questions are: (1) Are the published data underlying syntactic theories valid?, (2) How can we determine the source of acceptability judgment differences?, and (3) What do gradient judgments tell us about the architecture of the grammar? The hope is that these three questions will illustrate the fundamental connection between experimental syntax and theoretical syntax, provide concrete demonstrations of the value of the tools of experimental syntax (e.g., random sampling, factorial logic, and gradient judgments), and point to new directions for future research.