Much work has been done to capture the systematic variation in projective behaviors of factive inferences. However, not as much has been said about variation in factivity below the level of projection. This paper presents an experimental study which probes and confirms that Korean showcases patterns of variation in this vein: Factive inferences systematically arise from certain V+CPs, but only under certain prosody, even in unembedded contexts. Characterizing this pattern as prosodically-conditioned factive inferences, the paper proposes a pragmatic analysis of it couched in alternative semantics. The analysis motivates and defends a new interpretive principle which governs how alternatives come into contrast with each other, and re-examines the ontological status of factivity.