There has been considerable progress in second language (L2) research at the syntax-semantics interface addressing how syntax can inform phrasal semantics, in terms of interpretive correlates of word order (Slabakova, 2008). This article provides evidence of a flow of information ostensibly in the opposite direction, from meaning to grammar, at the interface between lexical semantics and syntax. It is argued that there is a functional hierarchy of modifiers in the domain of adpositions, which enables the linguistic elaboration of trajectories, but that not all languages lexicalize all types. This study examines whether L2 learners of English are able to overcome the poverty of the stimulus and recruit the relevant functional categories despite their absence in the first language (L1). Modifiers were taught to learners individually, but never in combination. A computer-animated narrative was designed in order to create felicitous contexts for combinations of modifiers, and preference and grammaticality judgment tasks were administered to 121 students from various L1 backgrounds, as well as 20 native speakers. Accuracy scores were remarkably targetlike on binary combinations of modifiers (1) across proficiency levels, (2) across L1s, and (3) across the two tasks, revealing that with the semantics of modifiers in place, the syntactic hierarchy is naturally manifested. (Contains 6 notes and 5 tables.)