复 合 句 名 词 从 句 疑问名词 what 1有疑问含义 2在从句中充当一定成分 3没有先行词（注：引导同位语从句有先行词） I don't know what you said at the meeting yesterday.
who I wonder who you meant .
whom Tell me whom you go to school with every day.
which They are twins.I can't tell which is which.
疑问限定词 whose I wonder whose idea it was.
which She asked me which one is the best .
what She doesn't know what book I like best.
疑问副词 where She is anxious to know where they had been just now.
when I wonder when and how we could get there .
why He never disclosed why he should do that.
how I don't know how I could get in touch with you .
连接词 whether 有含义不充当成分 It all depends on whether she likes her boss or not.
if (只引导宾从) I couldn't tell if she was crying or laughing.
as if/though(补从) He looks as if he were a boss.
that 无含义不充当成分 My motto is that contented with little yet wishing for more.
That he is a fool is known to all.
形 容 词 从 句 关系名词 who 1无疑问含义 He who laughs last laughs best.
whom 2有先行词 she is the girl whom(who) I love best.
which 3在从句中充当成分 A house which overlooks the park will cost more.
what(无先行词) Thank you for what you have done for me.
that 4关系名词和关系限定词若有疑问含义就会变为疑问名词和疑问限定词 He knows most that knows he knows little.
as I will provide you with such things as you may need.
than Do more than is expected.It will distinguish you from others.
but There is no man but loves peace in the world.
关系限定词 whose He is the man whose grammar book delights millions.
which He is learning economics,which knowledge is very important.
关系副词 where 5关系副词一旦失去先行词就会变为 连接副词 Wherever you are is my home,my only home.
when I've always longed for the time when I should be able to be independent.
why That is the reason why she didn't tell you the truth.
that This is the way(reason/place/time) that I did it.
副词从句 连接副词 where,because 1无疑问含义2无先行词 I can go where the wind blows me.
when,while,as I always feel better whenever I see you.
(so/such)that Her heart beat so that she could hardly breathe.
if,although,as if Although I gave her all I had,yet she was still not satisfied.