Languages constantly change, especially when they are spoken across generations and in contact with other languages. One striking site of such change is Differential Object Marking (DOM), the phenomenon whereby only some direct objects are overtly marked, typically depending on properties such as animacy, definiteness, or discourse prominence. In Romance languages, DOM has a long and complex history, often realised through the preposition a. Yet little is known about how these systems evolve when Romance varieties are spoken as heritage languages. This book explores DOM in heritage Italo-Romance varieties spoken in Argentina, where descendants of Italian migrants grow up bilingual and gradually become dominant in Argentinian Spanish, a language with an extended and productive DOM system. Rather than asking whether heritage speakers simply lose or borrow grammatical structures, the study traces how DOM reshapes itself at the intersection of grammar, discourse, and language contact.
Drawing on new fieldwork in Italy and Argentina, the book offers the first systematic comparison of DOM across several Italo-Romance varieties and their heritage counterparts. It shows that heritage DOM does not result from straightforward transfer from Spanish. Instead, contact accelerates changes already present in the homeland grammars, producing innovative yet constrained systems. A detailed case study of Friulian illustrates how DOM can emerge from structures linked to topicality and experiencer arguments, gradually extending to new contexts without replicating the Spanish pattern.
By combining syntactic theory, diachronic analysis, and fine-grained empirical data, this book shows how grammatical systems survive, adapt, and innovate in heritage languages.
