关系副词用于引导关系从句，连接主句和从句，包括"where"表示地点，"when"表示时间，"who"和"whom"表示人，"whose"表示所属关系，"which"表示物，"that"表示人或物。掌握这些关系副词的用法，可以更好地在英语写作和口语中表达自己的意思。
- where
表示地点，引导定语从句。例如：The hotel where we stayed was very comfortable.
- when
表示时间，引导定语从句。例如：The day when I met her was unforgettable.
- who
表示人，引导定语从句。例如：The man who spoke to me was very friendly.
- whom
也表示人，但是用作宾语时，引导定语从句。例如：The person whom I talked to was the manager.
- whose
表示所属关系，引导定语从句。例如：The girl whose bag was stolen is my sister.
- which
表示物，引导定语从句。例如：The book which I borrowed from the library is very interesting.
- that
表示人或物，引导定语从句。例如：The train that arrived late caused a lot of trouble.
