Language permeates human interaction, culture, behavior, and thought. The Foundations of Modern Linguistics Series focuses on current research in the nature of language. Linguistics as a discipline has undergone radical change within the last decade. Questions raised by today's linguists are not necessarily those asked previously by traditional grammarians or by structural linguists. Most of the available introductory texts on linguistics, having been published several years ago, cannot be expected to portray the colorful contemporary scene.