In this squib we examine the time course of children's acquisition of English to evaluate the basic insights of Kayne's (1981; 1984) proposals on preposition stranding. Kayne argued that the availability of preposition stranding (P-stranding) in English is parametrically linked to the availability of double object datives and the prepositional complementizer (PC) construction. We demonstrate that acquisitional evidence lends support to one component of Kayne's proposal, namely, that Universal Grammar (UG) contains a parameter that makes natural-language grammars permitting the PC construction a proper subset of those permitting P-stranding.