1) A sentence is a grammatical concept, and the meaning of a sentence is often studied as the abstract, intrinsic property of the sentence itself in terms of a predication. But when we think of a sentence as what people actually utter in the course of communication, it becomes an utterance.
2) While the meaning of a sentence is abstract, and de-contextualized, that of an utterance is concrete, and context-dependent. Utterance is based on sentence meaning; it is the realization of the abstract meaning of a sentence in a real situation of communication, or simply in a context.
3) Let's have a look at "My bag is heavy" as an example. The semantic analysis of the sentence results in the one-place predication BAG (BE HEAVY). The pragmatic analysis of the utterance will reveal what the speaker intends to do with it. The utterance meaning of the sentence varies with the context in which it is uttered. For example, it could be uttered by a speaker as a straightforward statement, telling the hearer that his bag is heavy. It could also be intended by the speaker as an indirect, polite request, asking the hearer to help him carry the bag. How it is to be understood depends on the context in which it is uttered and the purpose for which the speaker utters it.
1)句子是一个语法概念，句子的意义往往是作为谓语本身的抽象、内在属性来研究的。但是，当我们把一个句子看作是人们在交流过程中实际说的话时，它就变成了一种话语。
2)句子的意义是抽象的，脱离语境的，话语的意义是具体的，依赖语境的。话语是以句子的意义为基础的，它是在一个真实的交际情境中，或者简单地在一个语境中，实现句子的抽象意义。
3)让我们以“我的包很重”为例。句子的语义分析导致了一位述谓结构：包(重)。对话语的语用分析揭示说话人话语的意图。句子的话语意义因话语的语境而异。例如，发言人可以直接说出这句话，告诉听者他的包很重。这也可能是说话者的间接、礼貌的要求，要求听者帮他提包。它是如何理解的取决于它是在什么语景下说出来的，以及说话人说它的目的。
