This book examines traditional theories of linguistic vitality in the context of subcultural languages. It argues that traditional methods of investigating linguistic vitality are, according to existing literature, not as reliable as they appear and therefore limited in their testability. The author looks at themes such as the relationships between language and culture, ethnicity within the scope of sociolinguistics, and the notion of ideolinguistic vitality where traditional views intersect with more contextually current ones. She also highlights the importance of studying the nature and principles of subcultural languages which help better inform our understanding of the superdiverse linguistic world. The volume makes a major contribution to modern sociolinguistics by offering a detailed account of developing a unique measuring instrument to gauge the vitality of subcultural languages, which is applicable to more than just subcultural linguistics. An indispensable text in the study of ethnolinguistic vitality, the book will be of interest to students and researchers of sociolinguistics, applied linguistics, identity theory, philology, language and literature, cultural studies, and postcolonial studies.