In this chapter, we assume that systematically studying spatial markers semantics in language provides a means to reveal fundamental properties and concepts characterizing conceptual representations of space. We propose a formal system accounting for the properties highlighted by the linguistic analysis, and we use these tools for representing the semantic content of several spatial relations of French. The first part presents a semantic analysis of the expression of space in French aiming at describing the constraints that formal representations have to take into account. In the second part, after presenting the structure of our formal system, we set out its components. A commonsense geometry is sketched out and several functional and pragmatic spatial concepts are formalized. We take a special attention in showing that these concepts are well suited to representing the semantic content of several prepositions of French ('sur' (on), 'dans' (in), 'devant' (in front of), 'au-dessus' (above)), and in illustrating the inferential adequacy of these representations.