想要學好英語四級怎麼能不知道表語從句呢?下面就讓小編爲大家詳解一下吧。
表語從句構成方式：
若從句爲陳述句，直接加that;
若從句爲特殊疑問句：直接保留特殊疑問詞，後面的句子變成陳述句語序;
若從句爲一般疑問句：先把一般疑問句變成陳述句語序，然後在其前加上weather或者if;
eg：China is no longer what she used to be.
The question is who is responsible for what has happened.
一、表語從句的引導詞
引導表語從句的詞有連詞that, whether，連接代詞和連接副詞，關係代詞型what，以及as if, as though, because等連詞。
1. 由that引導
The fact is that he doesn’t really try. 事實是他沒有做真正的努力。
The trouble is that I have lost his address. 麻煩的是我把他的地址丟了。
My suggestion is that we should tell him. 我的建議是我們應該告訴他。
His sole requirement was (is) that the system work. 他唯一的要求是這個制度能起作用。
My idea is that we should start making preparations right now. 我的意見是我們馬上就開始做準備工作。
2. 由whether引導
The question is whether the film is worth seeing. 問題是這部電影是否值得看。
【注意】whether 可引導表語從句，但與之同義的if卻通常不用於引導表語從句。
3. 由連接代詞引導
You are not who I thought you were. 你已不是我過去所想像的人。
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 who (m) we should trust. 問題是我們應當相信誰。
What I want to know is which road we should take. 我想知道的是我們應走哪條路。
4. 由連接副詞引導
The problem is how we can find him. 問題是我們如何找到他。
That was when I was fifteen. 這是我15歲時發生的事。
That’s where I first met her. 那就是我第一次遇見她的地方。
That’s why he didn’t come. 這就是他沒有來的緣故。
That’s why I object to the plan. 這就是我反對這個計劃的原因。
That’s where you are wrong. 這就是你不對的地方。
5. 由關係代詞型what引導
That’s what I want to stress. 這是我想強調的。
That’s what we are here for. 我們來這裏就爲了這個。
Fame and personal gain is what they’re after. 他們追求的是名利。
He is no longer what he was. 他已經不是以前的`他了。
6. 由as if / as though引導
It isn’t as if you were going away for ever. 又不是你離開不回來了。
Now it was as though she had known Millie for years. 現在好像她認識米莉已有好多年了似的。
It is not as though we were poor. 又不是我們家裏窮。
7. 由because引導
It is because I love you too much. 那是因爲我太愛你了。
That’s because you can’t appreciate music. 這是因爲你不能欣賞音樂。
If I’m a bit sleepy, it’s because I was upall night. 如果我有點困，是因爲一夜沒睡。
It’s because I passed a slip of paper for John to Helen in class. 這是因爲我在上課中替約翰傳紙條給海倫。
【注意】because 可引導表語從句，但與之同義的since, as, for等也不用於引導表語從句。
二、連詞that的省略問題
引導表語從句的that通常不省略，但在口語或非正式文體中有時也可省略：
My idea is (that) we should do it right away. 我的意見是我們應該馬上幹。
The trouble is (that) he is ill. 糟糕的是他病了。