This paper gives a summary of the research situation and the main contents of presupposition,mainly introducing the study on the nature of presupposition,the types of presupposition triggers,and the theories about the presupposition projection,which comprise Karttunen\'s"Filtering Condition",Gazdar\'s"Cancelling Device",and Van der Sandt\'s theory.

Summary on presupposition trigger study of English and Chinese;

This paper discusses the presupposition theory in pragmatics and illustrates several aspects of the theory,including semantic presupposition,pragmatic presupposition,focus,mutual knowledge,the relations between presupposition and context,and presupposition triggers.

This paper proves why metaphor is a kind of presupposition trigger.

The relevance triggers are to relevantly stimulate the listeners by words,while the notional adverbs is the important composition of the relevance triggers.

This paper expounds how to lead the students to comprehend the presupposition triggers and the source texts from the viewpoint of semantic and pragmatic presupposition analysis by the examples in the author\'s translation class with the combination of presupposition features and the thinking motive of the students,i.