Abstract
Adpositions may govern case, and there is dramatic variation in the case values found. Different adpositions often govern different cases, which means that we need to partition (or split) the adpositions according to the case(s) they take, as in German. But this is just one possibility. The typological point of interest here is that the items governed (the governees) may also be a determining factor, as when nouns and pronouns require different cases, in Mari for instance. Furthermore, we may need to specify both the adposition and the governee (Russian). And then, rather than one fixed outcome, there may be alternating outcomes, for each of the three types of partition (adposition-based, governee-based, and splits based on both). At the extreme, even when we have specified a particular adposition, and an individual noun, we may still need further conditions. Here corpus work reveals the interesting interaction of determining factors, notably in Finnish. Our exploratory canonical typology lays out the possibilities, providing clear differentiation of the attested systems and subsystems. The specific example of adpositions can then be used as an entry point to approach unresolved issues in the more general area of differential marking.