The present study aimed to investigate (a) the extent to which Chinese-speaking learners of English in Taiwan use referential noun phrase (NP) information contained in discourse contexts to complete ambiguous noun/verb fragments in a sentence completion task, and (b) whether and when they use the contexts to disambiguate main verb versus reduced relative clause (MV/RRC) ambiguities in real time. Results showed that unlike native English speakers, English learners did not create a marked increase in RRC completions in biasing two-NP-referent discourse contexts except for advanced learners. Nevertheless, like native speakers, the learners at elementary, intermediate, and advanced English proficiency levels all used the information in a later stage of resolving the MV/RRC ambiguities in real time. The delayed effect of referential context information observed suggests that L2 learners, like native speakers, are able to construct syntax-to-discourse mappings in real time. It also suggests that processing of syntactic information takes precedence over integration of syntactic information with discourse information during L1 and L2 online sentence processing.