What do we know when we know a language? This class is an undergraduate level introduction to the scientific study of language. Throughout the course we will be attempting to identify the nature of the linguistic knowledge that every human being possesses, and to a lesser extent, we will study how humans use that knowledge in communicating with each other. We focus on the structure of language, and to this end we will acquire the methodological skills necessary for doing linguistic analyses on a wide variety of English and non-English language data. We will learn something about each of the major building blocks of linguistics: phonetics, phonology, morphology, syntax, and semantics. Once equipped with a way of talking about language, we will explore just how children acquire their language, how languages of the world are related typologically, and how their writing systems vary. We also discuss the tenuous relationship of language, thought, and culture. From our analyses, we will become acutely aware that certain universal principles permeate all components of human language.