A sentence is a grammatical concept, and the meaning of a sentence is often studies as the abstract, intrinsic property of the sentence itself in terms of predication. If we think of a sentence as what people actually utter in the course of communication, it becomes utterance, and it should be considered in the situation in which it is actually uttered or used. The meaning of a sentence is abstract and de-contextualized, that of an utterance is concrete and context-dependent. The meaning of an 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.