介词短语是介词连同其后的充当其宾语的名词及相当于名词的其他词类所组成的复合结构.
在句中可充当状语,定语,表语,补语.
examples:
(1):They leave in a hurry.( in a hurry方式状语)
(2):The apples on the tree look nice( on the tree定语)
(3)The book is under the desk.(under the desk表语)
(4)Make yourself at home.(at home补语)
也有做主语和宾语的.如
From the library to the teaching buiding is a 5 minutes' walk (主语)
The dog came out from behind the tree.(宾语)
希望帮到你!