【摘要】 英语中许多介词一形多义，其诸多的语义存在着结构与含义上的内在联系，语义范畴的扩展主要是透过象征和隐喻实现的，典型理论为其语义的扩展延伸提供了方法论。更多还原

【Abstract】 By using the prototype theory.this paper analyses the inner links of positional meanings of polysemous prepositions and relations between their extended meanings, and builds up a pattem which can demonstrates the course that meaning extend.更多还原