Common ground
Table of contents
Human language is characteristically a form of social interactive behaviour. It may occasionally have other functions, but the motivation for its coming into existence (see Dunbar 1996; Allan 2003) and by far the majority of its usage is when S (speaker, writer, signer) addresses utterance U to audience H for an unbounded number of perlocutionary and illocutionary purposes such as to establish or maintain a social relationship, to inform, question, demand, warn, apologize, and so forth. S and H are mutually aware that, normally, their interlocutor is an intelligent being. S does not need to spell out those things which are obvious to the sensory receptors of H, or such that H can very easily reason them out using the knowledge that each of us develops from birth as we experience the world around us on the basis of communicative competence (knowing the language and the conventions for its use). These constitute common ground (CG). Our understanding of linguistic utterances rests on an assumption of CG: e.g. when S points to something visible in the situation of utterance and says Isn’t that nice? there is an assumption that H understands English and can also see it; saying Let’s go to Brisbane assumes that ‘Brisbane’ will be understood as referring to a certain city. Some CG is universal, e.g. knowledge of the sun as a heavenly body that is a source of light and warmth, rain as (among other things) a source of fresh water replenishing the earth, the physiological and socio-cultural differences between the sexes. Some CG is very restricted, e.g. between a couple who use the wicked witch to refer to the man’s second wife. Usually S can readily assess the probable CG with H, and chooses his or her words accordingly. This requires S to make assumptions about H’s capacity to understand U well enough that S’s expressed intention in the message is, in S’s opinion, more or less correctly interpreted by H (Allan 1986; Lasersohn 1999; Colston 2008: 173). S’s assumptions here are S’s estimates of the CG between S and H with respect to U; this is not something S is normally conscious of except, perhaps, when communicating with a stranger – and not often then. Assumed CG is based on an assessment of H’s competence to understand U, and it motivates such things as choice of language and language variety, style and level of presentation – because, for instance, addressing a neophyte or a child must be differently handled from addressing a group of experts. CG allows meaning to be underspecified by S, so that language understanding is a constructive process in which a lot of inferencing is expected from H.