This chapter presents an overview of the main lingua francas of the world. The theoretical framework is Ecosystemic Linguistics, a branch of Ecolinguistics which sees language as communication or communicative interaction, not primarily as a system. The system does exist, but in order to facilitate understanding. It is shown that lingua francas such as Swahili, Fanakalo, Lingala, Kituba, and Sango (in Africa), Chinook Jargon, Mobilian Jargon, Nahuatl, Lingua Geral/Nheengatu, and Quechua (in the Americas), and Malay and Filipino (in Asia), among others, confirm this view of language. They are mainly used in situations of contact between speakers of mutually unintelligible languages, in which case the main concern is with mutual understanding, not with the construction of grammatical sentences. It is also shown that one of the main causes of the emergence of lingua francas is colonization.

This chapter generally deals with the borrowing of lexical items from English into varieties of North American oral French. First, the socio-historic context of English–French language contact in North America from the late eighteenth century to the present is described. Current demographics on French spoken at home in North America are then provided. An extensive review of the quantitative research on lexical borrowing in oral French in North America follows: the Eastern Townships of Quebec, the Ottawa-Gatineau region, on the border of Quebec and Ontario, Nova Scotia, the case of Chiac in New Brunswick, the community of Hearst in northern Ontario, French in Massachusetts and in Louisiana. In conclusion, the article attempts to compare a number of borrowing features in the communities studied, such as rate of lexical borrowing, grammatical category preference in borrowing, degree of morphological, syntactic and phonological integration, etc.

This paper synthesizes evidence for the origin and spread of the Indo-European languages from three disciplines – genomic research, archaeology, and, especially, linguistics – to reassess the validity of the Anatolian and Steppe Hypotheses. Research on ancient DNA reveals a massive migration off the steppe c. 2500 BCE, providing exceptionally strong support for the Steppe hypothesis. However, intriguing questions remain, such as why ancient Greek and Indo-Iranian populations had a smaller proportion of steppe ancestry, and Anatolian apparently had none at all. Lexical and archaeological evidence for wheels and looms provides essential clues about the early separation of Anatolian from the Indo-European community and the late entrance of Greek into the Aegean area. Evidence from the morphologies of the Indo-European languages supports these findings: the morphological patterns of the Anatolian languages show clear archaism, implying earlier separation, while the morphologies of Indo-Iranian and Greek display an array of similarities pointing to relatively late areal contact. Both the lexical and the morphological evidence, then, alongside the genomic and archaeological record, suggests that the Steppe hypothesis offers a preferable solution. Ultimately, these conclusions demonstrate the need for more dynamic models of change, including considerations of contact, stratification, and cross-disciplinary approaches.

There are a few hundred known sign languages around the world, and in such language communities, multilingualism is the norm. This multilingualism traverses modalities: signed, written, and, in some cases, spoken forms of language. Such a linguistic landscape inevitably leads to various forms of language contact between languages, including contact between two or more signed languages (characterised by lexical borrowing), signed language and spoken language (characterised by mouthings), and signed language and written language (characterised by fingerspelling, initialized fingerspelling). This chapter also covers sign language interference, code switching and code mixing, and the concept of bimodal bilingualism. The chapter concludes with a discussion of pidginization and creolization of sign languages and sign language endangerment, as well as general comments on the characteristics of contact between signed languages.

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.

The evolution of the Romance languages from Latin was significantly shaped by the numerous language contact environments, which resulted from conquest, colonization, and trade. This chapter traces the development of the largest Romance languages throughout Europe, with emphasis on the known or postulated effects of language contact. The chapter continues with an account of the spread of Spanish, Portuguese, and French to the Americas, together with the ensuing contacts with indigenous languages and languages of voluntary and involuntary immigration and the formation of Afro-Romance creole languages.

Language contact studies and historical linguistics, i.e. the study of language change, are subfields of linguistics that have long been recognized as being mutually relevant. This chapter explores this relationship along two dimensions: first, with regard to the fields of study themselves, and second, and perhaps more importantly, with regard to those aspects of language contact and of influence external to a given linguistic system that are particularly relevant to understanding the basic subject matter of historical linguistics, i.e. what happens to languages as they pass through time. In terms of the fields of study, an overview of the historiography of the distinction between internally motivated and externally motivated change is offered. This survey is followed by a discussion of several case studies, in which language contact serves as an actuator of change as well as some in which it is an inhibitor of change. Finally, the interaction of language contact with another key issue in historical linguistics, namely language genealogy, is discussed, along with a consideration of the naturalness and pervasiveness of language contact.

This chapter discusses – in the general problematics of languages in contact – Jewish languages and languages of the Diaspora. It intends to study from a comparative perspective especially the diachrony of Yiddish and Judeo-Spanish, two diasporic languages with similar developments and destinies. After a short presentation of the two languages, we examine successively: 1) the creation of Judaeo-languages in Diaspora, 2) the Diaspora versus migration, 3) the Judaeo-calque languages, 4) the common dynamics of Jewish languages, and 5) the diachrony of Jewish languages. The conclusion focuses on the successful innovations appearing in a Jewish language. It points out the important role of the Hebrew component (its direct and indirect influence), as well as the broad interlinguistic competence of Yiddish and Judaeo-Spanish speakers in the process of evolution of the languages considered.

The Portuguese began their colonial expansion early in the fifteenth century: by 1417 they had arrived in Africa. They settled islands and coastal areas in Upper Guinea in Africa by 1462, islands in the Gulf of Guinea by 1500, reached India by 1510, Malaysia by 1516, Indonesia by the 1520s, and Macau by 1555. As colonization progressed, the Portuguese introduced one or more varieties of their language in their settlements and trading posts, and over time these varieties of Portuguese have evolved lexically and structurally. Spoken varieties of Portuguese in Brazil, Angola, Mozambique, and East Timor have developed different patterns that are often consistent with patterns found in naturalistic second language acquisition. They also display unmistakable evidence of substrate influence. In addition, many highly restructured varieties, the Portuguese-based creoles, developed throughout Portugal’s colonial empire, some of which are still spoken today in Africa and Asia. Apart from the substrate influence apparent in the creoles, they have also developed many features unique to them as independent linguistic systems. In this contribution, the expansion of Portugal’s colonial empire and the evolution of all these Portuguese varieties will be presented and discussed.

Language contact is at its most intense within one and the same individual. This chapter discusses the dynamic and multifaceted phenomenon of individual bilingualism, which emerges when individuals learn to understand multiple language varieties. Individual bilingual language use may contribute to societal processes of language change, language maintenance, and language loss. It is as yet not fully clear how bilingual individuals affect such larger processes, but cross-linguistic influence in comprehension and production, patterns of language choice, and variable levels of proficiency across the lifespan all play a role. These in turn depend on individuals' contexts for learning and using languages throughout the lifespan. The chapter exemplifies some of these on the basis of bilinguals' language biographies (including Frederick the Great's). Language learning histories and opportunities for using each language help explain the large variability in language skills and use among bilinguals. New languages can be learned until well into adulthood. Their number is constrained only by learning opportunities and motivation. Previously learned languages, including languages learned very early in life, can be lost through lack of use and practice. Language attitudes play a large role in all of this.

Medieval and classical periods in African history are a particular focus of this survey of language contact patterns seen on the African continent. The effects of languages associated with empires and kingdoms are shown to vary widely, with many such languages remaining influential even in the present day. Disentangling earlier patterns of language contact is a necessary step for those interested in reconstructing and classifying African languages. The great time depth and diversity found within each of the major African language phyla is mirrored by a dizzying array of contact patterns both within and across these phyla.