Presupposition failures and the negotiation of the common ground

In pragmatics, it is a commonly accepted view that the cooperative activity of conversation is based on the “common ground” between the interlocutors - a concept that only apparently is uncontroversial. Described in cognitive terms as “knowledge of each other’s beliefs and attitudes” (Gibbs 1987) (or “shared knowledge”, see Kecskes and Zhang 2009) and at a logical level as a set of propositions whose truth is taken for granted and not subject to further discussion (Stalnaker 1974; von Fintel 2008), common ground is a challenge to any theory of presupposition or even implicatures. Despite its importance, very few studies have proposed alternatives to the cognitive or logical approaches, considering not only the relationship between an utterance and the granted information, but more importantly its dialogical and dialectical nature, which emerges when the ground is in fact not completely common. This paper intends to present an approach to common ground based on the notions of presumption and commitment: common ground is defined as a commitment that is presumed by the speaker to be held also by the interlocutor. However, presumptions are the result of a presumptive reasoning based on evidence of different types and resulting in different degrees of defeasibility - and thus “commonality.” Moreover, two different types of “grounds” presumed to be common can be distinguished, which are named “Shared” and “Communal” grounds. This approach can explain the conditions under which a proposition can be reasonably treated as part of the interlocutors’ commitments, and how this presumptive attribution can go wrong and needs to be explicitly discussed. Building on a corpus of intercultural dialogues among 8-10-year-old students, it will be shown how common ground is based on and results from a dialectical process through which the status of the interlocutors’ commitments are brought to light and negotiated.