Passive participles constitute an interesting body of data from the morpho-syntactic point of view as they combine adjectival and verbal properties, and consequently have to be endowed with rich morpho-syntactic structures. In this text we research the system of passive participles in Polish, clearly delimiting their verbal and adjectival properties. Then we concentrate on resultative states as a category with most puzzling mixed characteristics. Focusing on the resultatives derived from Object Experiencer Verbs, we argue for Intransitive Voice Projection in their structure. Some morpho-syntactic problems presented by these participles are solved when we consider a possibility that they code event kinds, rather than event tokens. Finally, the morpho-syntax of participles is juxtaposed with that of unaccusatives. The results support the kind of voice typology in which verbal structures may contain the intransitive voice projection, or lack voice altogether.