同学你好，该知识点来自沪江网校《新概念英语第三册【随到随学班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好
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）
He is the man whom/ that I saw yesterday.（whom / that在从句中作宾语，指人）

关系副词（when, where, why, that）可代替的先行词是时间、地点或理由的名词，在从句中作状语。
Beijing is the place where I was born.　（where在定语从句中作状语，指地点）
Is this the reason why he refused our offer?　（why在定语从句中作状语，指原因）

宾语从句的引导词有三类：
(1)   以that 引导的宾语从句，这里that只在（锐）从句中起联接作用，不在句中充当语法成分， that可以省略。
eg, The radio says (that) the clouds will lift later on.
　　She told me (that) she would like to go with us.
　　(2) 以连接代词which, what, who等或连接副词how, where, when, why 等引导的宾语从句，从句是陈述语序, 但是当连接词做主语时，仍是疑问语序。
　　eg, I want to know how soon it will begin.
　　Could you tell me what's the matter with you?       I don’t know who invented the map.
(3)   以 whether 或 if 引导的宾语从句, 主要用来引导一般疑问句意思或选择疑问句意思的宾语从句，从句同样是陈述语序　        
eg. I wonder if /whether you have told the news to Li Lei .

祝学习愉快哦