This paper investigates split ergativity in Laki (Northwestern Iranian). Present-stem verbs follow the accusative alignment and past-stem verbs follow the ergative alignment. We argue that T and v are two loci of agreement in the ergative alignment. As a result of an Agree relation with v, the φ-features of the external argument are realized as a clitic. However, we argue that obtaining agreement with T depends on the argument type and its accessibility to T. Normally, the objects remain low inside the vP phase and are inaccessible to T (Chomsky’s 2001 Phase Impenetrability Condition). Meanwhile, when the in-situ realization of deficient pronouns violates a clitic cluster restriction, they raise to the edge of the phase. This movement leads to an Agree relation between T and the pronoun. We show that deficient pronouns remain low only when their in-situ realization does not violate the clitic cluster restriction. In this vP-internal position, a deficient pronoun is inaccessible for an Agree relation with T, leading to its realization as a pronominal clitic. We show that agreement in Ardalani Kurdish closely parallels the agreement in Laki, except that it lacks a clitic cluster restriction. Without this restriction, a deficient pronoun remains in situ, and crucially its low realization consistently correlates with the absence of agreement. In line with previous findings (Johns 2000; Deal 2016; Haig 2017; Carrier 2020; Yuan 2022), we conclude that ergativity is not a unitary phenomenon. Rather, it should be characterized as a system resulting from the interaction between various parameters.
