How are Lexical-Semantic Differences Represented in L2 Syntax? A Study of the Unaccusative/Unergative Distinction in L2 Chinese

It has been proposed that intransitive verbs can be divided into two subgroups, unaccusative verbs, such as break and arrive, and unergative verbs, such as laugh and swim. The former type has an internal argument, but no external one, whereas the latter type has an external argument but no internal one. Unaccusative verbs are verbs of change of state or location, while unergative verbs are a set of agentive monadic verbs including verbs of manner of motion. In English, the internal argument of the unaccusative verb has to move to subject position to be Case-marked. In Chinese, however, the internal argument can remain in object position and get inherent partitive Case as long as it is an indefinite NP. External arguments of unergative verbs in both English and Chinese are in preverbal position whether they are definite or indefinite. The study reported in this paper was aimed at finding out whether the lexical-semantic distinction between the unaccusative verb and the unergative verb could be properly represented in English-speaking learners' L2 syntax of Chinese and whether the learner would only allow the single argument of the unaccusative verb but disallow that of the unergative verb to be in object position. The results indicate that the unaccusative/unergative distinction is acquired very late by English-speaking learners, and that the acquisition does not proceed in a linear fashion.