本文著眼於漢語句中詞組的句法結構以及其語用功能。透過句法和信息結構的互動關係，文中指出主題和焦點可以共存於介於主詞及謂語間的句中領域，同時也展現了和句首之主題焦點類似的語用功能以及句法限制。本文將 Rizzi (1997) 的左緣句構分析應用於句中詞組；文中所提出的分析能為前置受詞（preposed objects）和動詞複製結構（the verb-copying construction）的句法特性以及前人分析中未能解決的問題提出一致的解釋，並探討漢語不同語序間的信息結構和句法結構的對應關係。

This paper argues that Rizzi’s (1997) “fine structure of the left periphery” can be applied to the medial domain in Mandarin Chinese (i.e., the domain between TP and vP)and that this domain can license both Topic and Focus under distinct functional projections, with TopicP dominating FocusP. This paper explains theinformation-theoretic status of preposed objects by detailing the structural restrictions associated with the relevant topic and focus readings, respectively, and elaborating on
their differences. By adopting this joint approach – one which is different from previous analyses – I show that preposed objects can be either Topic or Focus in the medial domain. This paper then presents a unified account for the preposed object construction, the so-called verb-copying construction and various other related phenomena