A grammatical approach to topic and focus : a syntactic analysis with preliminary evidence from language acquisition
The goal of this dissertation is to argue on the basis of the minimalist framework that the topichood of sentence topics and contrastive focus result from derivational and structural differences in the left periphery and to provide acquisition data from child language to support this claim, showing data from Korean, a free word-order and pro-drop language in which topics and contrastive foci are realized morphologically. In Korean, topic phrases merge in the left periphery and contrastive focus phrases undergo scrambling, one of the shared properties of free word-order languages. It is consistent in fixed word-order languages such as Italian and Hungarian and a free word-order language like Korean that topics merge and contrastive foci move to the left. Topics precede contrastive foci: topics merge in TopP, a higher functional projection than FocP, to which focus phrases move. In the process of language acquisition, the derivational and structural differences between topic phrases and contrastive focus phrases may have influences on the developmental order of grammar acquisition. In acquisition data from two-year-old Korean children, topics emerge earlier than contrastive foci, indicating that topic and contrastive focus are also acquisitionally different. This study is the first attempt to examine the structural differences and the influence on language acquisition of morphologically derived topic phrases and contrastive focus phrases in acquisition data from a free word-order and pro-drop language. This study shows the structural consistency of topic and contrastive focus between a free word-order language and fixed word-order languages. The syntactic and acquisitional distinction of topic merge and contrastive focus movement is compatible with the semantic and pragmatic approaches to topic and focus. This study provides evidence of the syntactic differences between topic and contrastive focus without dependence on phonetic features; therefore, this study is a base for drawing a map of the left periphery of human languages.