Question

定语从句中怎样确定关系代词还是关系副词?

Answer 1

先把主句和定语从句分开,再找出定语从句所修饰的名词/代词（即先行词）,然后放入定语从句中,看看这两者的搭配情况.
1）如果定语从句和该先行词可以直接相连,且在从句中充当主语/宾语/表语的话,则用关系代词.
因为关系代词也属于代词,而代词功能同名词,在句子中一般充当语/宾语/表语.
如：This is the city (which/that) you visited last year.
定语从句所修饰的先行词是the city,放入定语从句you visited last year中,则它直接充当visited的宾语,变成：you visited the city last year.
2）如果定语从句和该先行词无法直接相连,必须另外多加上介词,并在定语从句中充当状语时,则使用关系副词.
如：This is the city where you stayed last year.
定语从句所修饰的先行词也是the city,将其放入定语从句中不能直接作成分,必须加上介词in,一起做从句的地点状语,即定语从句变为：you stayed in the city last year.