This volume studies the sociolinguistic features of mercantile languages and the traders’ role in language innovation during the medieval ages and early modern period. It also explores contact, mixing, and switching among a wide variety of mercantile languages used in Europe, Middle East, and Far East regions such as English, Latin, Italian, German, French, Spanish, Dutch, Danish, Scandinavian, Catalan, Provencal, Castilian, Flemish, Tuscan, Arabic, Hebrew, Yiddish, Aramaic, Malay, and Japanese.

The book consists of twelve chapters divided into four parts. Part 1, an introduction by Esther-Miriam Wagner & Bettina Beinhoff, foregrounds the vernacular features of mercantile languages and the sociolinguistic motivations underlying mercantile sociolects, such as the need for cross-boundary communication and for constructing a sense of belonging.

Part 2 focuses on the pragmatic literacy of the traders and their role as language trendsetters. Pragmatic literacy is shown in mercantile writing, with highly complex vernacular literature, used for work purposes, containing emotionally charged nonstandard colloquial expressions and cursive handwriting, as a result of both traders’ educational backgrounds (Merja Stenroos) and their choice of a writing style considered proper for business conduct (Esther-Miriam Wagner). Such pragmatic literacy has enabled traders to act as important agents in the innovation of various languages, either by introducing into written language various colloquial expressions and loan words to close-knit social networks (Wagner, José Miguel Alcolado Carnicero), or through language leveling, that is, the elimination of dialect forms in favor of more widespread ones in loose-knit social networks (Carnicero, Stenroos, and Wagner).

Part 3 explores mercantile multilingualism and code-switching, with articles by Ivar Berg, Laura Wright, Samull Kaislaniemi, Agnete Nesse, and Henrike Kühnert. It is found that, due to the traders’ geographical mobility and frequent contact with their partners of various language backgrounds, multilingualism becomes the norm in mercantile communication. Such multilingual communication is characterized by the profuse use of multilingual mercantile terminology, jargon, borrowing, and frequent code-switching, and, in the case of face-to-face communication, by receptive bilingualism with each interlocutor speaking his or her own language (Berg, Nesse). It is suggested that the code shift of mercantile communities towards particular languages may be attributed to pragmatic factors, such as affiliation with specific communities (Berg, Nesse), while stylistic change may be attributed to their consideration of the appropriateness of a specific mercantile register (Kaislaniemi).

Part 4 discusses the linguistic habits of mercantile communities. Mercantile documents are shown to be an important field that witnesses reciprocal influences between two languages (Megan Tiddeman). The choice of a particular language or sociolect for internal or external mercantile communication is considered as a strategic decision by both parties for a favorable outcome, largely dependent on the quality of the specific mercantile social networks, with loose-knit networks tending to promote vernacular or leveled forms while close-knit networks tend to maintain the use of traditional languages (Josh Brown). The existence of a presumed lingua franca has been challenged due to the lack of adequate evidence, which suggests that mercantile communication is based on the result of complex negotiation between traders of different language backgrounds rather than on a common pidgin (Rachel Selbach).