Abstract The goal of this paper is to provide novel theoretical and empirical evidence that the null subjects traditionally labelled as pro and pro, rather than being inherently distinct, are manifestations, differentiated in the course of the derivation, of what is underlyingly a single underspecified nominal pro-form, which we will call UPro. Included under this UPro are pro, oc pro and also the various types of ‘non-obligatory control’ (noc) pro, including arbitrary pro (proarb). The interpretive and distributional distinctions lurking behind these labels result from how UPro interacts with its structural environment and language-specific rules of morpho-phonological realization. Specifically, oc pro labels a rather specific interpretation that arises in embedding contexts where a syntactic oc relationship with an antecedent can be established. Different types of pro and noc pro, on the other hand, involve ‘control’ by (typically) silent representations of discourse-contextual elements in the clausal left periphery. Finally, proarb$_{arb}$ arguably involves the failure to establish a referential dependence, which we will formalize in terms of a failure to Agree in the sense of Preminger (2014). Crucial evidence motivating the approach proposed here will be adduced from Sundaresan’s (2014) “Finiteness pro-drop Generalisation”, which reveals an otherwise unexpected complementarity of oc pro and pro.

中文翻译：

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将pro和PRO减少到一个来源

摘要本文的目的是提供新颖的理论和经验证据，证明传统上被标记为赞成和赞成的无效主题，而不是本质上是不同的，是在推导过程中有所区别的表现形式，其本质是单个未指定的名义专业表格，我们称为UPro。此UPro中包括pro，oc pro，以及各种类型的“非强制性控制”（noc）pro，包括任意pro（proarb）。隐藏在这些标签后面的解释性和分布性差异是由于UPro如何与其结构环境和特定语言的形态语音实现规则进行交互。具体来说，专业人士标记了一种相当具体的解释，这种解释出现在可以建立与先行句法关系的嵌入上下文中。另一方面，不同类型的pro和noc pro涉及“控制”，（通常）通过从句左边缘的话语语境元素的无声表示进行“控制”。最后，proarb $ _ {arb} $可能涉及未能建立参照依赖性，我们将根据Preminger（2014）未能达成一致的观点来形式化。从Sundaresan（2014）的“ Finiteness pro-drop Generalisation”中可以得​​出激励本文提出方法的关键证据，该证据揭示了oc pro和pro的其他意想不到的互补性。我们将根据Preminger（2014）未能达成协议的形式正式化。从Sundaresan（2014）的“ Finiteness pro-drop Generalisation”中可以得​​出激励本文提出方法的关键证据，该证据揭示了oc pro和pro的其他意想不到的互补性。我们将根据Preminger（2014）未能达成协议的形式正式化。从Sundaresan（2014）的“ Finiteness pro-drop Generalisation”中可以得​​出激励本文提出方法的关键证据，该证据揭示了oc pro和pro的其他意想不到的互补性。