Some recent work has argued that agreement and case-assignment dependencies between a functional head and a nearby NP are not part of the syntactic derivation proper, but take place in the postsyntactic, morphological component of the grammar. I argue that this view is correct, by showing that one of its largely unexplored predictions has real empirical payout. The prediction is that the dependency-forming properties of functional heads, being morphological in nature, are mutable, and may be conditioned by nearby roots and functional structure. I focus here on Voice heads in Choctaw, and my starting assumption is that, by default, $ {\mathrm{Voice}}_{\left[+\mathrm{N}\right]} $ (the Voice head which introduces a specifier) agrees with its specifier (the external argument) and $ {\mathrm{Voice}}_{\left[-\mathrm{N}\right]} $ (i.e. specifier-less Voice, found in unaccusatives) does not agree with anything. However, I propose that in some environments, $ {\mathrm{Voice}}_{\left[-\mathrm{N}\right]} $does launch a $ \phi $-probe, and it results in $ {\mathrm{Voice}}_{\left[-\mathrm{N}\right]} $ agreeing with the internal argument. I refer to these configurations as ‘low ergatives’. A small survey of previous work on case and agreement dependencies suggests (a) that the case-assignment properties of functional heads are mutable in the same way, and (b) that the reverse is attested – in some environments $ {\mathrm{Voice}}_{\left[+\mathrm{N}\right]} $fails to launch a $ \phi $-probe. This is consistent with a purely morphological model of agreement and case-assignment: just as the exponence and interpretation of functional heads can be conditioned by adjacent roots and functional material, so too can the dependency-forming properties of those heads be conditioned in the same way.

最近的一些工作认为，功能头和附近的 NP 之间的一致性和大小写分配依赖并不是句法推导本身的一部分，而是发生在语法的句法后、形态组成部分中。我认为这种观点是正确的，因为它表明其很大程度上未经探索的预测之一具有真正的经验回报。预测是功能头的依赖形成属性，本质上是形态学的，是可变的，并且可能受附近的根和功能结构的限制。我在这里专注于乔克托的 Voice head，我的开始假设是，默认情况下，$ {\mathrm{Voice}}_{\left[+\mathrm{N}\right]} $（引入了说明符）与其说明符（外部参数）一致并且$ {\mathrm{Voice}}_{\left[-\mathrm{N}\right]} $（即无说明符的语音，见于非受格）不同意任何东西。但是，我建议在某些环境中， $ {\mathrm{Voice}}_{\left[-\mathrm{N}\right]} $确实会启动$ \phi $ -probe，它会导致$ {\ mathrm{Voice}}_{\left[-\mathrm{N}\right]} $同意内部参数。我将这些配置称为“低格”。对先前关于案例和协议依赖关系的一项小型调查表明（a）功能负责人的案例分配属性以相同的方式是可变的，并且（b）证明了相反的情况——在某些环境中$ {\mathrm{Voice }}_{\left[+\mathrm{N}\right]} $无法启动$ \phi $ -探针。这与一致性和案例分配的纯粹形态学模型是一致的：就像功能头的指数和解释可以由相邻的根和功能材料决定一样，这些头的依赖形成属性也可以在相同的条件下方法。