where the speaker really wants the hearer to understand the meaning:
“Can you lend me some money? I don't have much on me.”
The conversational implicature is a message that is not found in the plain sense of the sentence. The speaker implies it. The hearer is able to infer (work out, read between the lines) this message in the utterance, by appealing to the rules governing successful conversational interaction. Grice proposed that implicatures like the second sentence can be calculated from the first, by understanding three things:
* The usual linguistic meaning of what is said.
* Contextual information (shared or general knowledge).
* The assumption that the speaker is obeying what Grice calls the cooperative principle.
