This article presents obligatory control constructions in San Martín Peras Mixtec, a language in which PRO must be exponed with an overt pronoun. I propose a morphological analysis of this phenomenon in which this language lacks a null allomorph for bound minimal pronouns (Kratzer 2009, Safir 2014, Landau 2015, 2018), posited to underlie silent PRO in other languages. This suggests that null exponence ought not be ontologically tethered to PRO’s distribution or interpretation; rather, it can be reduced to the routine functions of language-specific contextual allomorphy.

Legate (2008) proposes that the postsyntactic component of the grammar plays an important role in morphological case phenomena. Therefore, it is predicted that postsyntactic processes like Linearization may affect morphological case assignment. I argue that this prediction is correct by demonstrating that prepositional case in Scottish Gaelic is assigned solely under linear adjacency with P. To account for this, I propose that Morphological Case Assignment is a postsyntactic process derivationally ordered after Linearization, as in Arregi and Nevins 2012 . This accounts for several typologically rare properties, such as the presence of closest conjunct case.