This chapter is about the evolution of language contact as a research area from the late nineteenth century to the present. It underscores the catalyst part that the discovery of creoles and pidgins by European philologists and other precursors of modern linguistics played in highlighting the roles of population movement and language contact as actuators of language change and speciation. It draws attention to the significance of the study of language evolution in European colonies in making evident the realities of language coexistence. These include the possible competition that can cause language shift and the death of one or some of the coexistent languages, a process that has affected competing European vernaculars faster than it has, for instance, Native American languages. It underscores the expansion of the field as linguists became interested in phenomena such as interference, codeswitching (or translanguaging), codemixing, diglossia, language diasporas, and linguistic areas, as well as factors that facilitate or favor the evolution of structures, sometimes of the same language, in divergent ways, owing to changes in population structures.

This chapter situates plurilingualism (at the individual level) and multilingualism (at the societal level), depending on the researcher’s approach to language contact, as enablers of various consequences of language contact. The relevant phenomena include language endangerment and loss (through language shift), codemixing and codeswitching (or translanguaging), the emergence of creoles, other mixed language varieties (including urban youth “stylects”), colonial varieties of European languages (such as Spanish), super-diversity, as well as structural change, borrowing, and the emergence of lingua francas. Concepts such as foreign workers’ interlanguages are contrasted with creoles and pidgins. Differences in their emergence are grounded in second language learning, degree and type of exposure to the hegemonic language, language shift, and the emergence of communal norms. The presentation in the chapter is generally grounded in population movements and changing population structures, therefore in speakers'/signers’ social history. It is also diachronic, explaining how domains of interest have evolved and expanded in language contact as a research area since the late nineteenth century, focusing on phenomena not elaborated in the chapters of Volume 1.

In this chapter the author revisits the concept of “super-diversity” from the perspective of colonial history. He presents the phenomenon as the outcome of the reversal of migrations, this time from especially the European former exploitation colonies to the European metropoles since the wake of World War II. The opposite direction of migrations had prevailed before, ignoring those of non-European enslaved and contract laborers from trade and exploitation colonies to settlement and other colonies. The author highlights differences in political and economic power associated with the differing directions of migrations, with the Europeans always having the upper hand, including in how to identify the migrants. Differences include the superposition of European languages as High varieties, associated with new communicative domains, over indigenous ones in the (trade and) exploitation colonies. This is in contrast with the marginalization and resentment of “allochthonous” languages in European urban centers, in addition to the stigmatization of the xenolectal and mixed character of the “autochthonous” language varieties produced by the migrants. The label “super-diversity” appears to reflect this fear of the foreigners from the colonies. Otherwise, the increase in societal multilingualism is not new. “Super-diversity” indexes the Othering of the immigrants.