介词短语:
指由介词＋介词、介词＋名词、介词＋分词、介词＋动词、介词＋形容词、介词＋副词等构成的短语,
常用的有：according to, along with,in front of,by means of,in spite of,together with,with regard to等.
介词短语是由介词加宾语构成,本身可作句子成分,如定语或状语等,可单独使用；
介词与其他词类或成分结合后方能在句子中充当语法成分,构成介词短语.介词短语可以作定语（须后置）、状语、表语、宾语补足语、另一个介词的宾语,间或作主语等.例如：
The skyscraper in the distance isa five-star hotel．（定语）
Her eyes were tired from long reading．（状语）
The decision is of great importance to me．（表语）
They found the machine in a bad state．（宾语补足语）
A pretty girl appeared from behind the curtain．（介词宾语）
On purpose or not on purpose is of great difference．（主语）