[…] ‘Inherent modality’ distinctions define relations between a participant and the realization of the SoA [state of affairs] in which he is involved. This distinctions may consist in the”ability” or the ”willingness” of a participant to do the SoA (“can”, “be able to/want”, “be willing to”), or in the question whether the participant is obliged (“must”, “have to”), or permitted (“may”, “be allowed to”) to do the SoA. Inherent modalities are not expressed by grammatical means, and belong to the internal structure of the predication. They are mainly discussed under Modality, because the predicate used to express these SoA-inherent features often develop into more strictly “modal” expressions over time.
- Dik (1989), a pag.205