Modality and facivity : one perspective on the meaning of the English modal auxiliaries
This study concentrates on modality as expressed by the set of modal auxiliaries and seeks to establish that these verbs share semantic as well as syntactic properties by identifying a single core meaning which they share. The relationship between modality and factivity is examined with the aim of gaining an insight into the former, more complex concept. When viewed from this perspective, the defining characteristic of all the modal auxiliary verbs in almost all of their uses is found to be nonfactivity. The meanings expressed by this set of verbs are classified according to a framework derived from modal logic consisting of three basic types of modality each of which relates to a different set of laws or principles; the relative factivity associated with the modal auxiliaries is seen to vary with the nature of modality as defined and classified by this framework. Within each of the three types of modality, a semantic scale is identified and modality is described as a gradable concept for which scalar analysis is appropriate, both within and beyond these three scales. Relative factivity is also shown to vary according to the degree of modality expressed by each of the modal verbs. The nature and degree of modality expressed interact with features of the linguistic (and pragmatic) context to determine the particular factive or a contrafactive interpretation conveyed by a given modal auxiliary token. The influence of certain combinations of contextual features is sufficiently strong to force a factive or contrafactive reading of a modal token, although in general the role of such features is merely to strengthen or weaken the relative factivity associated with the modal verb. Epistemic modality is seen to be most directly related to nonfactivity and therefore to be the most central modal meaning. The modal auxiliaries are found to be semantically less modal when they occur in contexts of determinate factual status. Least modal are those members of this set of auxiliary verbs which in certain uses have determinate factual status even without the presence of any of the significant contextual features.