“如果A ,就B”是表示分句间存在假设关系最具代表性的句式。本文在该句式语形分析的基础上 ,着重考察它的语义及语用特征。就语义特征而言 ,该句式主要表现为具有虚拟性和条件性 ;就语用特征而言 ,该句式可大致区分为求因假设和求果假设两类 “If A, then B” is the sentence that represents the most representative hypothetical relationship between clauses. Based on the morphological analysis of the sentence, this thesis focuses on its semantic and pragmatic features. In terms of semantic features, the sentence pattern mainly shows as virtual and conditional; for pragmatic features, the sentence pattern can be broadly divided into two categories, namely, the causal hypothesis and the causal hypothesis