Measuring the consistency of the “irrealis” domain

This paper applies semantic map methodology to the domain of irrealis in order to show,quantitatively, the extent to which emic irrealis categories vary across languages in terms of which functions they have. The amount and nature of variation among emic irrealis categories is compared with that in other domains, such as future or imperative. This study attempts to quantify how broad the irrealis category is in semantic space and how consistently it is encoded cross-linguistically. It will be seen that, while the conclusions here are sensitive to the input data, as is the case with any semantic map study, irrealis can be empirically characterized as a broad semantic domain with low consistency in terms of encoding by linguistic forms. This contrasts with the high consistency of its better-established sub-domains, such as future or imperative. While it is possible to create a notionally consistent cross-linguistic definition of irrealis meaning, as many authors have, none of these definitions reflects a category that languages prioritize in their TAM systems. This methodology can be used for any domain of semantic functions to evaluate its usefulness as a cross-linguistic notion.