The paper addresses the perennial problem of finding an adequate analytic approach to capturing many-to-many associations between form and meaning in a systematic manner, here focusing on the category of possessiveness. Based on close analysis of external possession in Czech, the study proposes a constructional network within a functional possessive space, in which related patterns are organized around shared features. Such a network provides a more refined map of criteria (syntactic, semantic, pragmatic, morphological) that collectively play a systematic role in expressing possessive relations in general, thereby also giving us a way of identifying the points of interaction between different constructions and thus articulating more precisely sources (as well as limits) of known ambiguities.