The aim of this paper is to explain case alternations on causees, illustrated in (1), which correlate with semantic alternations: the dative-marked causee is construed as being more volitional than and less affected than the accusative one:
(1) John-ga Tom-o/ni hasir-ase-ta. John-NOM Tom-ACC/DAT run-CAUS-PAST ‘John made /had Tom run’.
I adopt Role and Reference Grammar [RRG] (Van Valin and LaPolla 1997) as a framework which analyzes causative constructions such as (1). It classifies two-place verbs, depending on whether they have one or two macroroles (actor and undergoer). My proposal is that the complex verb comprising of the causative suffix -ase- and hasir- ‘run’ underspecifies the number of macroroles which it takes. In other words, (1) may take one or two macroroles, depending on its relative transitivity: the more affected the causee is, the more transitive (1) becomes and is more likely to take two macroroles, while the less affected the causee is, the less transitive (1) becomes and is more likely to take only one macrorole (actor). In the latter case, the causee receives non-macrorole status and takes dative case, the default case marker for non-macrorole arguments (Silverstein 1993). This analysis extends with no modification to analogous causative constructions in other languages and simple verb constructions and potential constructions in Japanese which embed transitive verbs.