A Unified Account Of Overpassivization Of English Unaccusative Verbs In SLA

This study investigates whether suggestion of external causation in contexts plays a role in English L2 overpassivization errors on unaccusative verbs. Based on lexical semantic theories (Pinker, 1989; Levin &Rappaport, 1995; Cai, 1998; etc.) and considering the effect of inferencing (Finer & Roeper, 1989; Ju, 2000), it is hypothesized that 1. Such errors are sensitive to verb unaccusativity strength which is presupposed in the study; 2. The degree of overpassivization in the context with strong suggestion of external causation differs significantly from that in the context with weak suggestion of external causation; 3. As learners become more proficient in L2, the more semantic knowledge they possess, the less they are affected by a cognitive factor such as inferencing.Three levels of Chinese learners of English, one comparison group adult native speakers and one reference group of child native speakers were asked to choose the more grammatical form (active or passive) in target sentences with 20 unaccusative verbs (correct in active form) and 20 transitive verbs (correct in passive form). Each target sentence with an unaccusative verb is embedded in two distinct contexts where suggestion of external causation differs. It was found that: 1.learners made more errors with peripheral unaccusative verbs than with core unaccusative verbs; 2. Error numbers in strong suggestion context vs. weak suggestion contexts were significantly different, though there were interaction effects from both verb groups and language levels; 3. Overpassivization errors decreased as learners advanced to a higher proficiency level.The pattern in which learners retreated from overpassivization errors indicates that overpassivization on unaccusative verbs is sensitive to their unaccusativity strength, and that a cognitive factor makes a dynamic impact on lexical semantic representation (LSR) of the verbs. Overpassivization arises from misconception ofLSR of the verbs. The degree of misconception can be significantly different in distinct contexts with strong or weak suggestion of external causation. It is also indicated that misconception decreases not only in the weak suggestion context but also in the strong suggestion context when L2 lexicon comes to resemble native lexicon and finally becomes steady.Unaccusativity is syntactically represented, but semantically determined in LSR. L2 LSR, that is, cognitive construal of events from L2 learners however, may deviate from native LSR. A cognitive factor such as inferencing of external causation from context information tends to stimulate L2 learners to form causativized unaccusative verbs, no matter they have transitive counterparts or not in their native lexicon. This thesis thus contributes to theorizing the overpassivization issue by providing empirical evidence in favor of the causativization account.