(7) π1 operators:
• provide additional specification of the SoA
[state of affairs];
• do not change the predicate frame of the
predicate to which they apply;
• are not expressed by lexical, but by
grammatical means;
• have the regularity of application and
expression which is commonly associated with
“inflectional” rather than “derivational”
processes. - Dik (1989), a pag.186