Abstract:
The study explored the acquisition of L2 English non-null arguments by L1 Thai learners, i.e. whether they were able to recognize sentences with null arguments and produce sentences with non-null arguments. Null arguments in Thai can appear in almost any sentential positions and the use of null pronouns in Thai are more preferable than the use of their overt counterparts, while arguments in the English formal register are not allowed to be omitted at all. It is therefore worthwhile investigating whether L1 Thai learners of L2 English can reject English sentences with null arguments and supply overt arguments in the ungrammatical sentences. Based on Markedness Differential Hypothesis (MDH), it is hypothesized that Thai learners have difficulty acquiring L2 English non-null arguments since argument dropping is unmarked while argument retention is marked. The study employed three variables which presumably affected the acquisition, namely animacy, clause types, and prepositional phrases (PPs). A grammaticality judgment task (GJT) and a Thai-English dialogue translation task (DTT) were administered to 31 intermediate and 31 advanced undergraduate L1 Thai students. The results from the GJT suggested that sensitivity to recognize null arguments increased with higher proficiency, whereas those from the DTT showed that both groups met the acquisition criterion of 80%. Paired-samples t-tests were performed to determine whether the three variables affected the acquisition. As for the intermediate group, it was found that clause types and PPs affected their judgments in the GJT, while animacy influenced their production in the DTT, adhering to an alignment of the universal animacy hierarchy and a reduction scale. It is proposed that perceptual saliency could account for the intermediate participants’ preference for null embedded subjects over null matrix subjects and that the lack of argument/adjunct knowledge could account for the intermediate participants’ preference for null object sentences followed by a PP over null object sentences without a PP following. As for the advanced group, it was found that clause types affected their judgments in the GJT. It is proposed that informal styles of communication influenced the advanced participants’ preference for null matrix subjects. It was also found that situation types of verbs affected the advanced group’s judgment on null object sentences. That is, they tended to omit objects of stative verbs more frequently than those of dynamic verbs, which was probably due to the fact that arguments of a dynamic verb are more salient than those of a stative one. In addition, the asymmetrical pattern of recognition and production can probably be accounted for by transfer of training.