Summary: In legal theory, it is a well-known idea that an intermediate concept like ‘ownership’ ‘couples’ a set $C_1,\dots, C_n$ of legal consequences to a set $F_1,\dots, F_p$ of legal grounds. In our paper we attempt to make the idea of a coupling between grounds and consequences more precise by formulating it as a relation holding between two lattices. In the first main part, we introduce the subject in an informal way by presenting a legal mini-system, where a structure of descriptive conditions is coupled to a structure of normative conditions. Subsequently, in the second main part, we introduce a more rigorous framework for conditions and develop the formal theory. In particular, we define and explain the notions of connection, coupling and coupling condition, as well as the relations ‘narrower than’ and ‘wider than’ between couplings.