This volume offers several empirical, methodological, and theoretical approaches to the study of observable variation within individuals on various linguistic levels. With a focus on German varieties, the chapters provide answers on the following questions (inter alia):Which linguistic and extra-linguistic factors explain intra-individual variation? Is there observable intra-individual variation that cannot be explained by linguistic and extra-linguistic factors? Can group-level results be generalised to individual language usage and vice versa? Is intra-individual variation indicative of actual patterns of language change? How can intra-individual variation be examined in historical data?Consequently, the various theoretical, methodological and empirical approaches in this volume offer a better understanding of the meaning of intra-individual variation for patterns of language development, language variation and change.The inter- and transdisciplinary nature of the volume is an exciting new frontier, and the results of the studies in this book provide a wealth of new findings as well as challenges to some of the existing findings and assumptions regarding the nature of intra-individual variation.

• Contents
• Introduction
• What Is Intra-individual Variation in Language?
• Part I: Phonetic-phonological dimension
• Everyone Is Different, So Everyone Is the Same – Intra-individual Variation in Second Language Acquisition
• Situational Effects on Intra-individual Variation in German – Reflexes of Middle High German ei in Austrian Speech Repertoires
• Linguistic, Social, and Individual Factors Constraining Variation in Spoken Swiss Standard German
• Part II: Syntactic-morphological dimension
• Intra-individual Variation in Nominal Inflection: Analyses of Directly Elicited Data of the Bavarian Linguistic Atlas
• Intra-individual Variation in Morphosyntax: A Constraint-based Perspective
• Inter- and Intra-individual Variation in Luxembourgish. A Quantitative Analysis of Crowd-sourced Speech Data
• Part III: Historical dimension
• Of Zibele and Bölle: Patterns of Language Variation in the Swiss Language Island New Glarus (North America)
• Intra-individual Variation in Nineteenth-century Private Letters
• Intra-individual Variation from a Historical Perspective: Towards a Usage-based Model of Constructional Change and Variation
• How many Natives with how many Systems? Intra-individual Variation and the Threshold of Multilingualism in Standard German Speakers
• Index