Samoan (Polynesian, Oceanic, Austronesian) zero-nominalizations have been shown to exhibit an exceptional tri-partite/inactive case alignment which distinctly marks unaccusative, unerga-tive and transitive subjects, where ergative subject maintain their ergative case from the verbal domain (Mosel 1992). Recently, Hopperdietzel & Alexiadou (=HA 2021) account for the tri-partite/inactive marking by the prepositional nature of ergative subject in syntactic ergative languages like Samoan (cf. Polinsky 2016). Therefore, ergative subjects obey the unaccusative requirement on nominalizations (Alexiadou 2001), contrasting with unergative DP subjects that must be merged in the nominal domain. In this talk, we present challenging data from possessive clitic pronouns in Samoan zero-nominalizations, which differ in their case alignment from their DP counterparts, in that the ergative case on transitive subject clitics (SCLs) is replaced by inalienable o-case, resulting in a double inalienable case pattern. Unergative SCLs however are still marked by alienable a-case (Mosel 1992). Based on the presence of the prepositional clitic pronoun =ina only in transitive nominalizatons, we argue that the possessive clitic pronoun is resumed in the verbal domain, enabling it to directly merge to D where it receives default inalienable o-case (cf. Baker 2015). In contrast, unergative SCLs violate the unaccusative requirement on nominalizations (Alexiadou 2001) and must be introduced by PossP, where they receive alienable a-case. Consequently, double default case in Samoan nominalizations supports both a prepositional analysis of syntactic ergativity and the unaccusative requirement on nominalizations.