Word order as an interface between syntax and pragmatics: The case of identifying topics in mixed case-marking patterns in Mandarin Chinese

•Word order in Mandarin serves as an interface between syntax and pragmatics, which is exhibited through the role that word order in Mandarin plays in marking case as well as topics.•Mandarin shows a mixed case-marking pattern through word order, namely that nominative-accusative pattern coexists with ergative-absolutive pattern, both of which allow intra-clausal topics and extra-clausal topics.•It is the intra-clausal topics rather than the extra-clausal ones that are associated with case-marking patterns, and hence topic assignment in unmarked constructions of different case-marking patterns can be identified.•In light of the two case-marking patterns, context-independent topics in various constructions can be identified. The typological classification of Mandarin Chinese as an isolating language lacking inflection brings about a theoretical consideration that word order in Mandarin serves as an interface between syntax and pragmatics. This paper provides from typological perspective a unified framework to examine the role that word order in Mandarin plays in marking case as well as topics. The study finds that Mandarin exhibits a mixed case-marking pattern through word order, namely that nominative-accusative pattern coexists with ergative-absolutive pattern. Both of the two case-marking patterns allow intra-clausal topics and extra-clausal topics, and it is the intra-clausal topics rather than the extra-clausal ones that are associated with case-marking patterns. With respect to the intra-clausal topics, in nominative-accusative pattern, topic assignment in unmarked constructions is A/S oriented, whereas in ergative-absolutive pattern, topic assignment in unmarked two/three-argument constructions is post-bă P oriented, and topic assignment in unmarked one-argument constructions is preverbal-S oriented. In light of the two case-marking patterns, context-independent topics in various constructions can be identified, and thus the controversial issue of distinguishing topics from other arguments can be properly addressed.