Firstly, the users including both the speaker and listener are closely related to conversational implicature. The speaker expresses the unspoken meaning or intention by exploiting conversational implicature, and the listener needs to force himself to understand the implied meaning in the utterance.
Secondly, the context plays a pivotal role in interpreting the implied meaning of an utterance. In other words, with varied contexts, the same sentence can correspond to different conversational implicature. For instance, the sentence “It’s cold here.” may imply the listener to turn down the air conditioner or to turn on it. Thus, the listener needs to consider what kind of context the utterance is in when identifying conversational implicature of a certain sentence, namely, its paralinguistic context and non-linguistic context. Paralinguistic context includes speaker’s facial expression, tones, gestures, etc. Non-linguistic context refers to the encyclopaedic knowledge that the interlocutors own and the situation that the communication happens.
Thirdly, correct inference is a necessity to decode conversational implicature. As for the effect of inference, Professor Cheng Yumin summarizes its function in three aspects: establishing the discourse coherence, interpreting ambiguity and generating conversational implicature. And Yule (2000:40) stated that the selected inferences are those that preserve the assumption of cooperation.
Levinson (1983) points out that conversational implicature can be categorized into two kinds according to its contexts, namely generalized implicature and particularized implicature. Together with the discussion above, the graph below illustrates the classification clearly:
合作原则视角下《唐顿庄园》中的会话含义分析(4):http://www.751com.cn/yingyu/lunwen_51646.html