This paper presents an experimental study on the interpretation of the spatialpreposition at in adult speakers, based on a variant of the Truth ValueJudgment Task. It is shown that speakers can interpret at as denoting a spatialrelation that stands in the “lexical entailment” relation with other spatial prepositions(e.g. inside, in front of, on top of, behind). For instance, if multiplelocated entities are involved in this relation, then they may occupy locationsthat can be “internal”, “external”, or placed on different verses of the samedirection, e.g. in front or behind a certain landmark object. It is discussed whichsemantic hypothesis correctly predicts these findings, and what the implicationscould be, for a theory of spatial prepositions and their Semantics.