话题的语篇连贯功能

语篇连贯必须以三种关联性为保证：语义关联、主题关联、语境关联，当连贯的外部条件和内部条件都得到满足时，语篇才能真正实现连贯。话题作为一个语篇功能成分，具有两个典型的语用特征，它能够通过不同的表现形式满足语篇连贯的外部条件和内部条件。

The Function of Topic in Achieving Textual Coherence

Textual coherence,which is based on three kinds of relevance,i.e.semantic relevance,topical relevance and contextual relevance,can only be achieved when both its external and internal conditions are satisfied.Topic,as a functional element of text,can help the text producer achieve coherence by various means,thanks to its two important features: aboutness and giveness.