In order to explain the unacceptability of certain long-distance dependencies – termed syntactic islands by Ross (1967) – syntacticians proposed constraints on long-distance dependencies which are universal and purely syntactic and thus not dependent on the meaning of the construction (Chomsky, 1977; Chomsky, 1995 a.o.). This predicts that these constraints should hold across constructions and languages. In this paper, we investigate the “subject island” constraint across constructions in English and French, a constraint that blocks extraction out of subjects. In particular, we compare extraction out of nominal subjects with extraction out of nominal objects, in relative clauses and wh-questions, using similar materials across constructions and languages. Contrary to the syntactic accounts, we find that unacceptable extractions from subjects involve (a) extraction in wh-questions (in both languages); or (b) preposition stranding (in English). But the extraction of a whole prepositional phrase from subjects in a relative clause, in both languages, is as good or better than a similar extraction from objects. Following Erteschik-Shir (1973) and Kuno (1987) among others, we propose a theory that takes into account the discourse status of the extracted element in the construction at hand: the extracted element is a focus (corresponding to new information) in wh-questions, but not in relative clauses. The focus status conflicts with the non-focal status of a subject (usually given or discourse-old). These results suggest that most previous discussions of islands may rely on the wrong premise that all extraction types behave alike. Once different extraction types are recognized as different constructions (Croft, 2001; Ginzburg & Sag, 2000; Goldberg, 2006; Sag, 2010), with their own discourse functions, one can explain different extraction patterns depending on the construction.

为了解释某些长距离依存关系的不可接受性–称为句法孤岛由Ross（1967）提出–句法学家提出对长距离依赖的约束，这种约束是普遍的和纯粹的句法，因此不依赖于构造的含义（Chomsky，1977; Chomsky，1995 ao）。可以预见，这些约束应适用于所有构造和语言。在本文中，我们研究了英语和法语跨构造的“主题岛”约束，该约束阻止从主题中提取。尤其是，我们使用跨结构和语言的相似材料，比较了从相对名词和从属问题中从名义主题中提取的内容与从名义对象中提取的内容。与句法解释相反，我们发现从主题中提取不可接受的内容包括：（a）在疑问句中提取（两种语言）；或（b）介词搁浅（英语）。但是，从两种语言的相对从句中的主语中提取整个介词短语都比从宾语中提取相似或更好。继Erteschik-Shir（1973）和Kuno（1987）等人之后，我们提出了一种理论，该理论考虑了所提取元素在当前结构中的话语状态：所提取元素是关注问题（对应于新信息），而不关注相对从句。焦点状态与受试者的非焦点状态（通常是给定的或话语陈旧的）相冲突。这些结果表明，以前对岛屿的大多数讨论都可能基于错误的前提，即所有提取类型的行为都相同。一旦不同的提取类型被认为是不同的构造（Croft，2001； Ginzburg＆Sag，2000； Goldberg，2006； Sag，2010），凭借其自身的话语功能，便可以根据构造来解释不同的提取模式。