Spatial language accounts aim to address both the meaning and usage patterns of spatial terms across diverse cases, but do not always clearly distinguish these from one another. Focusing on the prepositions in and on, we set out to disentangle spatial language meaning from use by comparing judgments on a series of linguistic tasks designed to tap each aspect of spatial language. We demonstrate that judgments of truth-conditional meaning and patterns of use show different distributional signatures: judgments of meaning give rise to a more uniform distribution than use patterns. We explore another judgment: lexical choice, and propose that choice is a key factor in shaping the distribution of spatial expression use. Our analyses reveal that patterns of choice judgments correlate with the patterns of expression use in spatial descriptions for the same spatial scenes, supporting a model of spatial language that differs from traditional accounts of meaning and categorization.