Book excerpt: "The primary goal of this book is to articulate a unified architecture for a model of second language phonology. By explicitly addressing the phonological interfaces, I will show how a common set of principles can account for diverse phenomena from phonetics, through to morphology and syntax. As we shall see, phonology is critical to these interfaces. I also hope to show that the empirical evidence strongly suggests that the phonological grammars of L2 learners is composed of rich, abstract, complex, hierarchical representations"--