This paper examines identical (copying) topic (IT) structure in Mandarin Chinese and Shanghainese. IT structure is very common in Sino-Tibetan languages and can be attested in all the diachronic and areal varieties of Chinese. IT consists of a nominal, verbal or adjectival element. Different syntactic categories are often neutralized at this position, nominals taking no referential encoding while verbals taking no tense/aspect marking. IT is semantically empty, and is usually in an unbounded state. It properly follows the principle of "Frame Being Bigger than Content". IT structure is a construction with one element occurring as both topic and focus, resulting in pragmatic roles such as emphasis, affirmation and concession. It also develops a linking function for coordinate clauses from the contrastive function of topics. IT results from the grammaticalization of conditionals. Violating the principle of linguistic economy, IT exists only in topic prominent languages. It is a better candidate for characterizing topic prominent languages than so-called Chinese style topics, i.e., non-gap topics.
本文考察汉语及上海话中的同一性(拷贝式)话题结构(IT)。IT结构在汉藏语系中很普遍,且遍及汉语之古今南北。IT由名、动、形等实词充当,不同词类在此位置出现特征中和现象,通常名词无指称成分、谓词无时体标记。IT是空义成分,通常属无界单位,符合“框架大于内容”的原则。IT结构是一种同一成分同时出现于话题和焦点的句式,导致肯定、强调、让步等语用功能,又由话题的对比性发展出并列连接等话语功能。IT来自条件小句的语法化。这种话题违背经济原则,只在话题优先语言中才存在,因此它是比所谓汉语式话题即无空位话题更典型的话题优先语言的特征。