This paper provides data from a regional dialect of Persian, Hamedanian Persian, where a verb is grammaticalized to be used as epistemic modality marker, frequently used in interrogatives. The verb didan, objectively means ‘to see’, but subjectivized in many instances to mean ‘understand’. However, in this dialect, bini, originally the subjunctive second person singular form of the verb didan ‘to see’, is used as epistemic marker. It is used in content and polar questions, where uncertainty is a common feature. Our fieldwork data show that the verb didan is used rarely to mean ‘to see’ and it extended to mark epistemic modality, used as probability marker. This modal marker is only used in questions, which share the stance of uncertainty with epistemic markers. The various features of this grammaticalization path are discussed and an explanation based on egophoricity is provided.
