Differential object marking: an overview

The present paper aims to provide an overview of Differential Object Marking (DOM) and Differential Object Indexation (DOI), which have been a recurrent research topic in linguistic typology in the past few decades. Various theories that have been put forward to account for DOM and DOI are presented and critically discussed based on cross-linguistic data. The article also discusses two recent studies that have emphasised the role of information structure parameters, such as topicality, in determining the distribution of DOM and DOI. In particular, it is argued that the optionality found in DOM systems is sometimes only apparent, in that the presence vs. absence of DOM depends on its information-structural status, namely topicality. Finally, some diachronic paths that lead to the emergence of DOM and DOI systems are examined, and a number of selected issues relevant for future research are discussed.