Abstract:
Based on the Thinking for Speaking hypothesis (Slobin, 1996; 2003), this dissertation investigates the acquisition of Thai subsidiary non-deictic directional verbs /khɨn3/ up and /loŋ1/ down by native English speakers learning Thai as a second language. It aims to categorize and contrastively analyze differences in meanings of these subsidiary verbs in Thai and those of directional words up and down in English, and to investigate interference of L1 thinking for speaking patterns on the use of the two Thai subsidiary verbs by high and low proficiency L1 English learners. This dissertation is divided into two main parts. In the first part, corpus data of the Thai subsidiary non-deictic directional verbs (/khɨn3/ and /loŋ1/) and the English directional words (up and down) are analyzed with respect to their meanings. It is found that these terms have three main senses, namely, directional meaning, quantitative meaning, and aspectual meaning. However, due to differences in semantic extension, certain meanings are observed only in one language, but not the other. For example, up contains a sense of approaching (as in move up), which is not found with the Thai verb /khɨn3/. Moreover, data also show differences in terms of frequency of meanings used in Thai and English. The second part concerns data collection from two groups of L1 English learners of Thai (a high proficiency group and a low proficiency group) using a translation test and tasks involving a pair discussion and picture description. It is revealed that the two groups of learners can use the subsidiary non-deictic directional verbs in the three main senses, but their use of aspectual meaning is limited. Furthermore, while the high proficiency group uses /khɨn3/ and /loŋ1/ as a subsidiary verb in a serial verb construction most frequently, the low proficiency group does not. They instead prefer using one main verb in a sentence. This reflects the interference of English thinking for speaking patterns in the low proficiency learners. The high proficiency learners, on the other hand, seem to be able to adapt to Thai thinking for speaking. In conclusion, the results of this dissertation support the Thinking for Speaking hypothesis. In second language acquisition, the process of Re-thinking for Speaking needs to be gradually systematized. Learners proficiency level plays an important role in that high proficiency learners who have more experience with L2 will be ble to aquire L2 thinking for speaking patterns and more able to re-think for speaking than low proficiency learners.