Changes in social structure often lead to mobility and migration. Urbanisation is one important outcome of mobility and migration. Mobility, migration and urbanisation lead to dialect contact, that is, between speakers of mutually intelligible varieties. This chapter first introduces general concepts such as diffusion and supralocalisation, and then moves on to discuss sociolinguistic models developed for the analysis of dialect contact, including the theories of koineisation and new-dialect formation, based on principles such as accommodation and salience. Case studies are taken from medieval Spain, Early Modern New Mexico and twentieth-century Norway. The chapter also addresses the role of new speakers in contact situations, based on an example from sixteenth-century Tuscany, and ends with a short discussion of sociolinguistic typology.

Different texts have different characteristics. In this chapter, we first explore the concepts of register, genre and style, which are, in the tradition of Biber, linked to communicative functions and situational characteristics. The co-occurrence of register features and dimensions are introduced as the linguistic indicators of communicative functions. A particularly useful approach to register centres around keyness, which we demonstrate with historical Portuguese data. We then introduce discourse traditions as a historical-linguistic concept closely related to genre and register. We use French literary examples to explain stylistic differences and the link with the Labovian distinction between indicators, markers and stereotypes. This leads to a discussion of indexicality and indexical fields more generally, for which we draw on ancient Greek plays. The chapter continues the discussion of the literary representation of language variation on the basis of English texts comprising dialect, and explains the important concept of enregisterment.

This chapter discusses standardisation as a major factor in sociolinguistic history. After a brief dicussion of basic concepts such as diglossia, Ausbau, Abstand and diaglossia, we introduce the Haugen model, including the key concepts of selection, codification, elaboration and acceptance. We go on to argue that the later introduced concept of implementation is crucial in analyses of the interaction of norms and language use in the language community. Focusing on this interaction, and based on case studies from English and Dutch, three scenarios are distinguished: prescriptive influence, prescriptive delay and concurrent prescriptivism. The chapter ends by situating the interaction of norms and usage into the wider framework of the total linguistic fact as developed by Silverstein.

In this chapter, we focus on multilingualism and language contact, moving away from the strong focus on monolingualism characteristic of many traditional approaches to language history, and discussing various onsets, scenarios and outcomes of language contact. We introduce the concepts of borrowing and imposition as central constructs to understand contact-induced change in language, illustrating and critically examining these ideas in three case studies: the development of loanwords in Canadian French, Germanic substrate effects in the formation of American Englishes and mixed-language business writing in medieval Britain after the Norman Conquest. Building on these cases, we discuss which elements of the language can be transferred and explore possible pathways of social diffusion of borrowings, as well touching upon various traits and examples of code switching and similar multilingual practices in historical texts. Finally, we evaluate the constructs of pidgin and creole languages, discussing to what extent they can be seen as different in structural terms, or whether their distinctiveness arises primarily from the sociohistorical circumstances from which they arose.