This article presents a new perspective on the derivational source for transitive verbs of possession. These are commonly postulated to be derived from a preposition expressing possession by incorporation of the preposition into an auxiliary. I reframe the contrast between prepositional and verbal expression of possession as an opposition between dependent and head marking of the possession relation, implemented syntactically as marking of either the specifier or the head of the projection encoding the possession relation. This conclusion is inferred from an investigation of Syrian Arabic showing that morphemes expressing possession alternate between a prepositional and a verbal use, but the verbal use does not involve incorporation of functional material. Evidence is presented that languages that show such incorporation, that is, where possession is expressed by a term of the form AUX+P, have passed through a diachronic stage similar to contemporary Syrian, where P functions as a verb in its own right. These considerations support the conclusion that transitive verbs of possession are not derived by P-incorporation, but by reanalysis of dependent marking as head marking, which may or may not feed incorporation.