BE able to and the categorization of modal markers in English. A corpus-based study

The aim of this paper is to investigate the role of BE X TO structures in English via the analysis of the quasi-modal BE ABLE TO. Based on previous accounts of the marker and its comparison with modal auxiliary CAN, defining characteristics are identified and contrasted with the description of other BE X TO structures such as BE ALLOWED TO and BE LIKELY TO. Consequently, the availability of non-finite forms along with property attribution and goal orientation stand out as unifying properties of the BE X TO quasi-modal category, which occupies a singular place within the modal system of English.