Experiential constructions is an understudied topic in western Austronesian languages. The focus is on Northern Amis (Formosan), with some crosslinguistic comparison. In Amis, experiential constructions are derived by a syncretic suffix-en, which is also an Undergoer Voice suffix. In experiential constructions,-en is suffixed to stative-intransitive verbs compatible with experiences, and functions as an applicative voice that licenses an extra-thematic experiencer marked as the nominative argument, generally with adverse meaning. Though reminiscent of adversative passives in some Asian languages, experiential constructions in Amis are not passives, nor are they standard Undergoer Voice-en constructions for two main reasons: (i) they are restricted to stative and intransitive stems; (ii) their argument structure and case-marking are different. It is argued that the source of Amis experiential constructions is a Proto-Austronesian adversative *ka-…-an/-en construction (Blust, Robert. 1999. Notes on Pazeh phonology and morphology. Oceanic Linguistics 38(2). 321-365) and that Amis innovated by creating a verbal ma-…-en experiential applicative construction from that originally non-finite construction.