The PoP is an inner-complement construction.

Diagram 2: Postpositional phrase
N P
[ noun phrase postposition ]PoP
inner complement head

Kinds of postpositions

To classify postpositions, the following criteria are employed:

  1. Syntactic function of the postpositional phrase: Most postpositions signal whether the phrase headed by them functions as a complement or as an adjunct. This produces the classes of grammatical vs. concrete postpositions.
    • Inside concrete postpositions, a subclassification into event-oriented and participant-oriented postposition obtains.
  2. Morphological structure of the postposition: A monomorphemic postposition is primitive. Postpositions comprising more than one morpheme are complex.
Table 1: Classes of case relators
syntactic function
morphological structure ╲
 grammatical concrete
primitive + +
complex - +

→ Grammatical postpositions are primitive; complex postpositions are concrete.