回答如下：
介词短语作定语时，一定要置于所修饰词之后，即作
后置定语。但是，名词之后的介词短语不一定都是定语，有可能是宾补，有可能是状语。例如：
The girl in red (定语)is my daughter.
We will wait at the gate of the school( 定语 ).
We went to the zoo by bus ( 状语).
He does well in maths ( 状语 ).
We found her at work ( 宾补).
I saw the man in the chair ( 宾补).