In this paper we investigate the occurrence of Greek and Hebrew locative expressions in two syntactic frames: (i) direct complementation, and, (ii) complementation mediated by a 'light' P(reposition). The main claim is that these two frames correspond to two Case mechanisms: PF Case licensing in the domain of a prosodic word, and syntactic Case checking via a light P, respectively. We attribute the particular implementation of each frame to the different syntactic status of locatives in each language; Hebrew locatives are argued to be P heads, while their Greek counterparts are phrasal modifiers. Consequently, direct complementation resulting in PF Case licensing is widely attested in Hebrew, because most Hebrew locatives are construct heads, forming a Construct State, namely, a single prosodic word, with their complements. Direct complementation is limited to clitics in Greek, because only they can be part of the prosodic word of the locative. Syntactic Case checking via a light P is widespread in Greek because Greek locatives are phrasal, therefore, unable to check Case of their DP complements in syntax. The same mechanism is limited in Hebrew to a particular variety of locatives, which are argued to be free P heads, lacking a Case feature. (c) 2007 Elsevier B.V. All rights reserved.