I like the book （which I bought）. 我喜欢（我买的）这本书
This is the man （who studied with me）. （关系代词做主语）
This is the man （with whom I studied）. (关系代词做宾语)
=This is the man （whom I studied with）.
The man (who you’re talking to ) is my friend.
The man （to whom you’re talking ）is my friend.
I need a pencil （with which I can write a letter）--很地道
= I need a pencil (which I can write a letter with).
I need a piece of paper （on which I can write a letter）.---很地道
=I need a piece of paper (which I can write a letter on).
The man (who/whom/that 都可以) I talked about at the meeting is from Peking University.
=The man （about whom I talked at the meeting）is from Peking University.
The palace (which/that 都可以) I often pay a visit to was built in the 17th century. =The palace to which I often pay a visit was built in the 17th century.
每个动词都有很多的介词搭配，比如：look at, look up ,look into, look down,look forward 等