This monograph offers a comprehensive account of the L1-acquisition and use of yes-no questions in English from a usage-based, construction grammar perspective. On the basis of the BNC and a high-density, longitudinal CHILDES corpus, the book explores two issues which have largely been neglected in previous research: 1. the prevalence of non-canonical questions (such as elliptical and declarative questions) in adult-to-adult as well as child(-directed) speech and the L1-acquisition of these structures. 2. The discourse-functional properties of both canonical and non-canonical yes-no questions, especially with regard to their influence on the acquisition process.