This paper deals with the influence that nominal and verbal parameters have on DOM in the diachrony of Spanish. Comparing selected corpus studies, I will focus first on the different nominal parameters that build up the animacy and referentiality scales, in particular on animacy and definiteness. In order to clarify how far DOM has diachronically evolved, special attention will be paid to inanimate objects, which can be viewed as the alleged endpoint in the development of DOM in Spanish. Secondly, I will provide a systematic overview of the relevant verbal parameters, which include aspect, affectedness and agentivity. The study will show a complex interaction of nominal and verbal parameters, revealing some unexpected correlations: Obligatory object marking is not only found with human and strongly affected objects involved in a telic event, but also with inanimate, non-affected and agentive objects embedded in a stative event. In other words, in Spanish DOM patterns with both extremely high and extremely low transitivity. These findings sharply contrast with traditional accounts concerning the development as well as the explanation of DOM.