In grammaticalization studies, reanalysis is understood as the assignment of new meaning to formally unchanged elements, supported by bridging contexts compatible with the old and the reanalyzed meaning. The source determination hypothesis (SDH) predicts that parallel grammaticalization trajectories occur crosslinguistically, as similar source meanings give rise to similar inferences. One such pattern is the development of recent past markers from FINISH constructions. While grammaticalization pathways are well-documented crosslinguistically, the SDH has never been tested experimentally. In this study, we examine whether modern English speakers are sensitive to inferences arising from a bridging context identified as relevant to the grammaticalization of Old Spanish FINISH into a recent past marker. In a temporal distance judgment task, we examined whether the bridging context identified for Old Spanish facilitates an inference of temporal immediacy in contemporary English, where the construction has not been grammaticalized. In line with the SDH, the bridging context enhanced an inference of immediacy in contemporary English (Exp. 1), with specific grammatical features of the source determining its strength (Exp. 2). These results not only demonstrate the viability of testing hypotheses about language change using experimental pragmatics but also call for empirically refining the concept of source determination.