differentiating evidentiality and epistemic modality based on the behavior of persian adverbials

this paper attempts to indicate that the two conceptual categories of evidentiality and epistemic modality are distinct although they may look similar; thus their corresponding adverbs also consist of separate subcategories of adverbs. to attain this goal, different data were gathered both from written and spoken sources and analyzed mostly with the help of semantic considerations in the framework of functional typological approach. vanvalin (2005)’s argument regarding the order principle dominating the functional elements and the interaction of evidential and epistemic modality operators with their corresponding adverbs and therefore considering two distinct subcategories of evidential and epistemic modal adverbs are in line with the results of this study. in contrast with previous studies which view the relationship of the two categories as one of inclusion or overlapping, the current project argues that epistemic assessment of the speaker should not be confused with evidential considerations since evidentiality has to do with the information source. also it can be argued that various levels of reliability should not be equated one to one with different degrees of epistemic commitments of the speaker because the epistemic modal expressions and their corresponding adverbs are somewhat the evaluation of the likelihood while the evidentials evaluate the reliability of the information source. eventually we must draw a line between the two categories and their relating adverbs and see them as separate groups.