When we try to analyze how hedges work, we usually talk about speakers implying something that is not said. Similarly, in considering what the woman meant by a sandwich is a sandwich, we decided that she was implying that the sandwich wasn’t worth talking about. With the co-operative principle and the maxims as guides, we can start to work out how people actually decide that someone is “implying” something in conversation. Consider the following example.

On the face of it, Steve’s statement is not an answer to Bob’s question. Steve doesn’t say Yes or No. Yet Bob will immediately interpret the statement as meaning “No” or “Probably not.” How can we account for this ability to grasp one meaning from a sentence that, in a literal sense, means something else? It seems to depend, at least partially, on the assumption that Steve is being relevant and informative, adhering to the maxims of Relation and Quantity. (To appreciate this point, try to imagine Bob’s reaction if Steve had said something like Roses are red, you know.) Given that Steve’s original answer contains relevant information, Bob can work out that “exam tomorrow” conventionally involves “study tonight,” and “study tonight” precludes “party tonight.” Thus, Steve’s answer is not simply a statement about tomorrow’s activities, it contains an implicature (an additional conveyed meaning) concerning tonight’s activities.

It is noticeable that, in order to describe the conversational implicature involved in Lara’s statement, we had to appeal to some background knowledge (about exams, studying and partying) that must be shared by the conversational participants. Investigating how we use our background knowledge to arrive at interpretations of what we hear and read is a critical part of doing discourse analysis.