Book excerpt: This book examines the syntactic properties of the English preposition to and the Romanian preposition la ”at/to” within ditransitive structures. Being a study of comparative syntax from a generative perspective, it aims at bringing into discussion the properties of these two functional prepositions, in both English and Romanian. The comparative approach shows that the English to is a functional preposition, fully predictable from the structure of the verb which can be deleted. To is a case marker and the dative arguments introduced by this preposition are DPs. By way of contrast, Romanian la has shifted from a case marker to a [Person] marker. La has a double status, as follows: it has a functional status only when the Dat argument, analysed as DP can be doubled by the clitic, where la is a [Person] marker. In the absence of the clitic, la-phrases are interpreted as PPs and la will be attributed a lexical status. Thus, unlike the functional to, la is both (a) a functional dative marker and (b) a core lexical preposition of the location and movement frames where la assigns accusative case to its object.