From the introduction: "In this paper I will examine case marking strategies in Kope, a Papuan language of Papua New Guinea, in light of claims made by Foley (1986:92-98). Foley makes a basic distinction between 'core' and 'peripheral' case relations in his typological study of case marking in the Papuan languages of New Guinea. Core relations include actor and undergoer, while peripheral relations include instrument, locative, and temporal. Syntactically, Foley claims that most Papuan languages have one strategy for marking core relations, and another strategy for marking peripheral relations.
"A third group of relations discussed by Foley includes the beneficiary and recipient relations. Foley (1986:98) refers to these as 'middle-ground' relations on the basis that in some languages they are marked according to the strategy for core relations, while in others they are marked according to the strategy for peripheral relations. Foley does not discuss any languages in which these relations are marked according to a separate strategy.
"In sect. 2 of this paper I show that, in line with Foley's claim, Kope follows different strategies for marking core as opposed to peripheral arguments. Then in sect. 3 I show that the beneficiary, recipient, and addressee relations are also marked as core arguments in Kope. In addition to normal agreement marking, however, the presence of these relations also triggers the presence of the verbal prefix Va-. In sect. 4 I outline the wider use of this prefix. Finally, I discuss some typological implications of this marking system in sect. 5."
Clifton, John M.
"Case marking strategies in Kope,"
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 34, Article 1.
Available at: https://commons.und.edu/sil-work-papers/vol34/iss1/1