Incremental production has been a recent topic in language production studies. There are several levels in the sentence production process, such as the conceptual level, syntactic formulation level, phonetic formulation level, and so on. In incremental sentence production frameworks, a fragmental, incomplete segment can trigger a part of the sentence production process. For example, since an input to the syntactic formulator may be lacking case information on the noun to be produced, the syntactic formulator must complete the missing case information in order to produce an utterance incrementally. Furthermore, if the completed information causes inconsistency with the actual case information to be supplied later, the syntactic formulator must somehow dissolve this inconsistency. To examine how these processes are done in human sentence production, we conducted psycholinguistic experiments on incremental sentence production. Consequently, we found that the completion of missing case information is performed in a regular way, where a nominative case is assigned to the leftmost element in the sentence, and that the dissolving of inconsistency is done by means of passive voice construction or self-repair.
