Ccmnunication involves the interaction between (a) a speaker who produces an utterance in order to express a proposition and (b) a hearer who listens to that utterance and duly processes it to reach an understanding of that proposition. This understanding should optimally correspond with the proposition which the speaker intended to express in order for successful ccmnunication to take place. The relationship between what the speaker intends and what the hearer understands essentially determines the outcome of a communication attempt. If what the hearer understands to have been expressed differs from what the speaker intended to express, that speaker's ccrnrnunication attempt has not been successful: a misunderstanding has occurred. The speaker's communication attempt need not irredeemably fail because the hearer has misunderstood his utterance. Conversations consist of exchanges of utterances and consequently the speaker can endeavour to correct the hearer's understanding of his utterance, providing that he is aware that the misunderstanding has occurred. Thus the speaker's communication attempt might ul tirnately be successful although initially it was unsuccessful.