This paper explores the advantages of a dynamic notion of context in which not only shared knowledge, but also accommodation of assumptions has a central role. To this end, we analyze the interpretation of tautologies: according to the literature, their interpretation is based on prior knowledge. By contrast, our hypothesis is that shared knowledge is neither a necessary nor a sufficient condition for the felicitous uses of a tautology. To support our view, we conducted a corpus study and an interpretation questionnaire with two experimental tasks. The results align with our predictions