This work studies unaccusative predicates taking dative arguments in Spanish and presents three related claims. First, it is shown that dative arguments (analyzed as applicatives) with unaccusative predicates correspond to three different types which are distinguished semantically. Second, it is argued that there are three different kinds of (underlying) unaccusative structures: psychological (as with gustar 'like', importar 'matter'); predicates of change and existentials (crecer 'grow', faltar 'lack'); and inchoative (romperse 'break, intr.', derretirse 'melt, intr.'). Finally, a systematic interaction is revealed between the type of unaccusative construction and the type of dative argument. In particular, contrasts among the structures arise from differences in the licensing position of the arguments. The common subject properties of dative DPs derive from their being the higher argument and from their final subject position, not from being all licensed as an external argument. These structural differences, in turn, generate semantic differences with respect to the interpretation of the dative DP and the predicational properties of the construction. Unaccusativity is thus revealed as an epiphenomenon, not corresponding to a unique underlying structure.