Linguistic studies of evidentiality, the coding of source of knowledge, have often appeared divided into two camps: those whose focus is the semantic, morphological and typological characteristics of grammaticalized morphological evidential systems, and those whose focus is on the social functions of non-grammaticalized evidential constructions as markers of epistemic authority and responsibility. While interest in the discourse functions of all evidential systems has been growing as seen in the recent special issue of the journal Pragmatics and Society on ‘Evidentiality in (...) Interaction’, there has been little direct attention on whether the deployment of evidential strategies in discourse varies according to the grammatical status of the grammatical resources available to the speaker. This article examines the nature of both grammaticalized and non-grammaticalized evidential systems in a number of languages to show that while the underlying pragmatics of evidentiality is the same regardless of grammatical system, nonetheless grammaticalized evidential systems provide important evidence of the particular features of knowledge sources that are used in routine ways in discourse sufficiently to motivate their development into grammatical systems. (shrink)