表語從句用法講解
1、表語從句概述
用作表語的從句叫作表語從句，它位於主句中的連系動詞之後。引導(dǎo)表語從句的詞有從屬連詞that、whether、as though(if)；關(guān)系代詞who, what, which, whom, whose, whatever, whoever, whomever, whichever等；關(guān)系副詞when, where, why, how, however, whenever, wherever等?？梢越颖碚Z從句的連系動詞由be, look, remain, seem等。That引導(dǎo)表語從句時，在口語中，間或可以省略。
The trouble is that we are short of money.睏難是我們資金短缺。
That is why stone walls are used instead of fences around New England fields.這就是爲(wèi)什麼在新英格蘭用石頭牆而不用柵欄的原因。
At that time, it seemed as if I couldn't think of the right word anyhow.儅時,我似乎怎麼也想不出一個恰儅的字眼來。
2、由從屬連詞that，whether引導(dǎo)的表語從句。
that在引導(dǎo)表語從句時無詞義，而whether有詞義，意爲(wèi)、“是否”。這時主句的主語常常是些抽象名詞，如question(問題)，trouble(麻煩)，problem(問題)，result(結(jié)果)，chance(可能性)，suggestion(建議)，idea(想法)，reason(理由)等。表語從句對主句主語進(jìn)行說明、解釋，使主語的內(nèi)容具躰化。
The trouble is (that) she has lost his money. 麻煩的事是他丟了錢。
The question is whether we need more ice cream.問題是我們是否還需要一些冰淇淋。
The problem was that it was too valuable for everyday use.問題是它作爲(wèi)日常之用太貴重了。
What she couldn’t understand was that fewer and fewer students showed interest in her lessons. 我們不能理解越來越少的學(xué)生對他的課不感興趣。
3、由關(guān)系代詞引導(dǎo)的表語從句。
關(guān)系代詞who, what, which, whom, whose, whatever, whoever, whomever, whichever等引導(dǎo)表語從句，在句中作主語、賓語、表語，關(guān)系代詞不能省略。
The question is which of us should go.問題是我們哪一個應(yīng)該去。
The problem was who could do the work.問題是誰能做這項工作。
That's what he is worrying about.那就是他在擔(dān)心的事。
That's what we should do.那是我們應(yīng)該做的。
4、由關(guān)系副詞引導(dǎo)的表語從句。
Go and get your coat. It's where you left it. 去把雨衣拿來。就在你原來放的地方。
I had neither a raincoat nor an umbrella. That’s why I got wet through. 我們既沒繖也沒雨衣，這是我們淋溼的原因。
That is how mice ruin many stores of grain every year.那就是老鼠是怎樣每年損害大量糧食的。
That is what he is worried about.那就是他所擔(dān)心的。
5、由連詞because，as if/as though等引導(dǎo)的表語從句。
It looked as if it was going to snow.看起來好像要下雪了。
That's because we never thought of it.這是因爲(wèi)我們從未想過此事。
It seems as if he didn’t know the answer.好像他不知道答案。