This paper examines the development of five hearsay evidential markers in Korean, namely, tako, tamye, tamyense, tanun and tanta, and traces their extended pragmatic functions in discourse. We first identify their functions over time, from Middle Korean to Modern and Contemporary Korean, then quantitatively analyze the usage frequency of these functions, diachronically from the 16th century to the early 20th century using the UNICONC historical corpus, and synchronically in present-day Korean using the Sejong contemporary written and spoken corpus. From a pragmatic perspective, we examine how Korean speakers use these hearsay evidential markers to convey the interpersonal and intersubjective stances of interlocutors in natural conversations. Based on the differential rates of grammaticalization of these markers, and on their usage frequency, we also examine the relationship between evidentiality marking and finiteness; more specifically, we analyze the sequences and mechanisms of change whereby different types of non-finite evidential structures develop into finite evidential constructions. Our findings have broader theoretical and crosslinguistic implications for understanding the mechanisms of insubordination, whereby dependent structures become independent, and whereby lexically transparent constructions develop into grammaticalized markers of speakers’ stance.