Dutch adverbialising suffixes -gewijs and -erwijs are alleged to stand in
complementary distribution in that the former attaches to nouns, whereas
the latter combines with adjectives. This article claims that this historically
merely allomorphic pair of suffixes acquired another important distinction,
of a syntactic nature, which has thus far been overlooked in the literature:
whereas -gewijs derives predicate adverbs, -erwijs derives sentence adverbs.
Occasional exceptions to this distinction can easily be predicted on morphological
grounds. The whole process is to be considered a typical instance of
subjectification (see e.g. Stein & Wright 1995) and possibly of exaptation
(Lass 1990) as well. Evidence is drawn from historical corpus inquiry.