Introduction to Special Issue From language mixing to fused lects: The process and its outcomes Peter Auer University of Freiburg, Germany Nikolay Hakimov University of Bamberg, Germany Abstract Objectives: In this introductory article, we advance a unified framework for analysis and inter- pretation of transfer of overt linguistic structure in language contact situations. Our goal is to demonstrate that fusion, a process whereby results of bilingual practices become grammaticized and conventionalized (see Auer 1999, 2014), is a gradient phenomenon, which applies to a large spectrum of language contact phenomena. Our additional objective is to situate the contributions to this special issue in the context of this approach. Design: The article defines fusion as a central concept underlying the proposed framework, identifies the basic dimensions of fusion and showcases its various outcomes by reviewing extensive contact linguistics literature and the contributions to this special issue. Data and Analysis: In our analysis of contact linguistic phenomena, we draw on available lin- guistic descriptions of pertinent contact varieties and bilingual practices. We examine these phenomena in terms of fusion and in relation to its three basic dimensions. Findings: This article shows that fusion, being a gradient multifaceted phenomenon, should be analyzed along the following dimensions: (a) the amount of structure affecting the receiving lan- guage, (b) the degree of sedimentation of bilingual patterns, (c) the degree of fusional compartmentalization. Significance: The present article identifies and describes manifold outcomes of fusion in terms of three basis dimensions. These dimensions enable one to distinguish fused lects from language mixing and other bilingual phenomena and need therefore be incorporated in future linguistic descriptions and analyses of fused lects. Keywords Language mixing, language fusion, borrowing, mixed languages Corresponding author: Peter Auer, University of Freiburg, Albert-Ludwigs-Universita ¨t Freiburg, Deutsches Seminar, Postfach, Freiburg, 79085, Germany. Email: peter.auer@germanistik.uni-freiburg.de International Journal of Bilingualism 1–8 ª The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1367006920924943 journals.sagepub.com/home/ijb