区别是：关系副词在定语从句中做状语，关系代词在定语从句中做主语后者宾语。他们和关系代词主要的区别是where,when,why=介词+which。
1、关系代词（that, who, whom, whose, which）所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。
例一、Is he the man who/that wants to see you?（who / that在从句中作主语，指人）
例二、He is the man whom/ that I saw yesterday.（whom / that在从句中作宾语，指人）
例三、They rushed over to help the man whose car had broken down.（whose在句中作定语，指人）
例四、Please pass me the book whose cover is green.（whose在句中作定语，指物。）
2、关系副词（when, where, why,）可代替的先行词是时间、地点或原因的名词，在从句中作状语。关系副词when, where,why的含义相当于"介词+ which"结构，因此常常和"介词+ which"结构交替使用。
例五、Beijing is the place where (in which) I was born.
例六、Is this the reason why (for which) he refused our offer?
例七、His father died the year (when / in which) he was born.
例八、He can’t find the place (where / in which) he lived forty years ago.
二丶判断用关系代词和关系副词
用关系代词，还是关系副词完全取决于从句中的谓语动词。缺少宾语，就必须要求用关系代词；不缺成分（作状语）用关系副词。
方法一： 用关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后面无宾语，就必须要求用关系代词。
例如：（错） This is the mountain village where I visited last year.
（错） I will never forget the days when I spent in the countryside.
（对） This is the mountain village (which) I visited last year.
（对） I'll never forget the days (which) I spent in the countryside.
习惯上总把表地点或时间的名词与关系副词 where, when联系在一起。此两题错在关系词的误用上。
方法二： 准确判断先行词在定语从句中的成分(主、谓、宾、定、状)，也能正确选择出关系代词/关系副词；先行词在从句中作主、定、宾语时，应选择关系代词；先行词在从句中作状语时，应选择关系副词。
例如：（对）Is this the museum which you visited a few days ago?
（对）Is this the museum where the exhibition was held?
扩展资料
关系代词（that, who, whom, whose, which）所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。
Is he the man who/that wants to see you?（who / that在从句中作主语，指人）
关系副词（when, where, why,）可代替的先行词是时间、地点或原因的名词，在从句中作状语。
关系副词when，where，why的含义相当于“介词+ which”结构，因此常常和"介词+ which"结构交替使用。
Beijing is the place where (in which) I was born。用关系代词，还是关系副词完全取决于从句中的谓语动词。缺少宾语，就必须要求用关系代词；不缺成分（作状语）用关系副词。