定语从句“介词+关系代词”引导的定语从句，是定语从句一种介词前置的定语从句句型，介词与关系代词之间存在一种介宾关系。当关系代词在定语从句中作介词宾语时，把介词置于关系代词前，即演变出“介词+关系代词”句型。例如： The man who/whom /that you spoke to is a teacher. =The man to whom you spoke is a teacher.一、基本构成1.“介词+关系代词”结构引导的定语从句中，关系代词只能用 which（指物）或 whom(指人) ，即：介词+which/whom。 1）The man to whom you spoke is a teacher.2）The city in which she lives is far away.3）The little girl is reading a book,in which there are many cartoons.注意：当介词放在关系代词的前面时，用在介词后的关系代词不能省略。，当介词置于定语从句的谓语动词之后时，可用 that/which(指物)；that/who/whom（指人）作介词的宾语.且此处关系代词可以省略，特别是在口语中。如： 1) The man (who/whom /that )you spoke to is a teacher.2）The city（which/that）she lives in is far away.注：通常介词放在定语从句中动词后，也可以放在关系代词前面，但有些特别动词短语搭配不能拆分，介词只能放在动词后，如： look for, look after, pay attention to ,take care of , look forward to, listen to 等。1）This is the pen that / which you are looking for.2）The patient whom she is looking after is her father. 3）The words that /which we should pay attention to are written on the blackboard.4）There are fifty patients who/whom/that we must take good care of.二、关系副词 when，where，why 可用“介词＋which”来代替。关系副词实际上是介词＋先行词。其中when=表时间的介词（如：in，at,during 等）+which；Where=表地点的介词（如：in，at,on,under 等）+which；Why=表原因的介词（如：for）+which 1．当先行词表示时间，定语从句中缺少时间状语时，通常用关系副词 when 引导，此时也可选用表示时间的介词＋which 来代替关系副词 when。 I still remember the day when I came here. ( on the day =when) 2．当先行词表示地点，定语从句中缺少地点状语时，通常用关系副词 where 引导，此时也可...
