This article investigates optional ergative marking in Tujia, an endangered Tibeto-Burman language spoken in south-central China. It is shown that the Agent in Tujia is optionally marked, and that the use of the optional ergative marker ko 35 is multifunctional. It is used to disambiguate the semantic role of Agent, to emphasize agency, and to focalize an Actor in a discourse context. Several factors, including word order, telicity, perfectivity, verbal semantics, information structure and discourse-pragmatics, play a role in determining the use or non-use of the ergative marker. Secondly, the historical source of the optional ergative marker is explored. It is hypothesized that the morpheme lie 21 was originally an instrumental marker whose meaning became extended to encompass the marking of ergativity. Later, this morpheme lost its ergative meaning, after the third person singular pronoun ko 35 acquired the role of optional ergative marker, as a result of language contact with Chinese. The analysis may enhance the understanding of the variety of uses and the sources of ergative case marking in Tibeto-Burman languages in general.
- Indexical elements