1． 定義：用作主語的從句叫做主語從句.
2． 構(gòu)成：關(guān)聯(lián)詞+簡單句
3． 引導主語從句的關(guān)聯(lián)詞有三類：
(1) 從屬連詞that.如：That they were in truth sisters was clear from the facial resemblance between them.
很明顯,她們確是親姐妹,她們的臉型很相似.
(2) 從屬連詞whether.如：
Whether he’ll come here isn’t clear.他是否會來這里還不清楚.
(3) 連接代詞who,whom,whose,what,which,whoever,whatever,whichever
連接副詞 where,when,how,why.如：
What she did is not yet known.她干了什么尚不清楚.
How this happened is not clear to anyone.這事怎樣發(fā)生的,誰也不清楚.
Whoever comes is welcome.不論誰來都歡迎.
Wherever you are is my home ---- my only home.你所在的任何地方就是我的家----我唯一的家.
1． 定義：用作同位語的從句叫做同位語從句.
2． 用法：同位語從句的先行詞多為fact,news,idea,thought,question,reply,report,remark等,關(guān)聯(lián)詞多用從屬連詞that.如：
They were all very much worried over the fact that you were sick.
對你生病這件事,他們都很焦慮.
Where did you get the idea that I could not come?
你在哪兒聽說我不能來?
Early in the day came the news that Germany had declared war on Russia.
德國已對俄國宣戰(zhàn)的消息一大早就傳來了.
注：同位語從句偶爾由從屬連詞whether引導.如：
I have no idea whether he’ll come or not.我不知道他是否來.
連接代詞who,which,what和連接副詞where,when,why,how亦可引導同位語從句.
The question who should do the work requires consideration.
誰該干這項工作,這個問題需要考慮.
We haven’t yet settled the question where we are going to spend our summer vacation.
到哪兒去度暑假,這個問題我們還沒有決定.
It is a question how he did it.
那是一個他如何做了此事的問題.
1． 定義：用作表語的從句叫做表語從句.
2． 構(gòu)成：關(guān)聯(lián)詞+簡單句
3． 引導表語從句的關(guān)聯(lián)詞的種類：
(1) 從屬連詞that.如：
The trouble is that I have lost his address.麻煩是我把他的地址丟了.
(2) 從屬連詞whether,as,as if.如：
He looked just as he had looked ten years before.他看起來還與十年前一樣.
The question is whether they will be able to help us.問題是他們是否能幫我們.
注：從屬連詞if一般不用來引導表語從句,但as if卻可引導表語從句,如：
All this was over twenty years ago,but it’s as if it was only yesterday.
這都是20多年前的事了,但宛如昨天一樣.
能跟表語從句的謂語動詞一般為系動詞be,seem,look等.如：
It looked as if it was going to rain.看起來天要下雨了.
(3)連接代詞who,whom,whose,what,which,whoever,whatever,whichever
連接副詞 where,when,how,why.
如：The problem is who we can get to replace her.問題是我們能找到誰去替換她呢.
The question is how he did it.問題是他是如何做此事的.
That was what she did this morning on reaching the attic.那就是她今晨上了閣樓干的.