Abstract
The present study focuses on a grammatical category called evidentiality. The primary meaning of evidentiality is concerned with information source. That is, it expresses whether something has been seen, heard or inferred. The aim here is to conduct a conceptual study of evidentiality in which use is made of formal tools. The fundamental intuition is that the distinction between ‘evidence’as ‘proof’and ‘evidentiality’as ‘to do with proof’is a crucial one. Evidentiality is a dynamic notion to be analysed through the use of knowledge by the agents, a knowledge in action, which involves an in-coming state and an out-coming state that is typical of the transmission of information. We propose our own approach in which the dynamics of knowledge in action is grasped in the context of a dynamic epistemic logic.