The aforementioned inflectional case system only goes so far on its own, and rather serves as that upon which is built a system of agglutinative suffixes or particles known as postpositions, which parallel English's prepositions. It is their use with a noun or verb that necessitates the noun or verb taking the oblique case (though the bare oblique is also sometimes used adverbially), and it is with them that the locus of grammatical function or "case-marking" then lies. There are eight such "one-word" primary case-marking postpositions.