首先要明确的是WHAT在名词性从句中是一定要作成分的，而THAT则起连接作用。
名词性从句分为四类：主语从句、宾语从句、同位语从句和表语从句。WHAT多引导主、宾、表语从句。
例句一中WHAT引导的是一个宾语从句[是作GOT TO的宾语]，而WHAT在从句中则充当的是主语。
意思就是，三个月后，他们抵达了[那个叫做彩虹的地方]并安顿下来了。中间括起来的都是抵达的宾语，而在这个宾语从句中又是WHAT作的主语。
例句二中WHAT引导的也是宾语从句[作SPENT的宾语]，而在从句中也是作主语。
下面是一些资料，如果有不懂的可以发消息给我：）
1． 意思是“所….的事/物”, 相当于the thing(s) that…, that which…, 或those which… 可以用于以下情况：
(1) 引导主语从句。如：
What she saw frightened her. 她看到的事情吓了她一跳。
What I’m afraid of is their taking him to that place. 我怕的是他们带他到那地方去。
But what hurt our feelings most was the personal comment of the judge.
最伤我们感情的是法官的私下评论。
What is gone is gone. 过去的事就过去了。
(2) 引导表语从句。如：
That’s what I hope. 那就是我希望的。
I should like to be a teacher. That’s what I want to be. 我想当老师，那是我想干的事。
Times are not what they used to be. 时代不同了。
He’s not what he was a few years ago. 他不是几年前的他了。
Your health is not what it ought to be. 你的身体应该更好。
(3) 引导宾语从句，包括介词宾语。如：
He could not express what he felt. 他不能表达他的感受。
Well, I’ll do what I can. 好吧，我尽力。
The father began to criticize what the boy had done. 父亲开始批评男孩所做的事。（注意时态）
She was not happy at what he had said. 她对他说的话不高兴。
Don’t poke your nose into what doesn’t concern you. 不要多管闲事。
The city is different from what it was ten years ago. 这座城市和十年前不同了。
It was a small place then compared to what it is now. 和现在比起来，它那时候是个小地方。
Philip was depressed by what he had gone through. Philip经历过的事情使他很消沉。
They paid fifty percent of what they were able to earn to the state.
他们能挣来的东西，百分之五十交给了国家。
2． 用作插入语，指代后面的成分。这和非限定性定语从句正好相反，非限定性定语从句指代的是前面的成分。如：
Then I discovered, what was news to me, that his wife was Mary’s niece.
后来我发现，他妻子原来是Mary的侄女，这对我是个新闻。
He’s an interesting speaker, and, what is more important, he knows his subject thoroughly.
他讲话生动有趣，更重要的是，他对课题了如指掌。
He went to the meeting and, what was worse, insisted on speaking.
他去参加了会议，而且更糟糕的是，他坚持要发言。
It is a useful book, and, what is more, not an expensive one. 这是本很有用的书，再说也不贵。
We invited a new speaker and, what’s more, he was happy to come.
我们请到了一位新的发言人，而且他很乐意来。
3、引导让步状语从句，等于“不管什么…”。注意状语从句的语序。如：
Do what she would, she could not invent a reason for not going. 不管她会做什么，她都编不出不去的理由。状语从句把实义动词放在句首，句子倒装。＝No matter what she would do, …
Come what may, you’ll always keep it secret.
无论怎样，你都要保守秘密。＝No matter what may come, ….
Say what he will, in his heart he knows that he is wrong.
不管他怎么说，内心里他知道自己错了。= No matter what he will say, …
4、从高考题看 what 引导名词性从句的特殊含义
请看下面一道高考题:
After________seemed a very long time, I opened my eyes and found myself in bed!
A. what B. when C. that D. which
答案是A。大家知道,what引导名词性从句,意为"所……的事",相当于"the thing that...; all that...; everything that...."等。如:
What was once regarded as impossible has now become a reality.
过去认为不可能的事现已成为现实。
下面对它所引导的名词性从句的特殊含义略作归纳。
一、表示"……的人",相当于"the person that..."。如:
1.He is not what he was a few years ago. 他不是几年前的他了。
2.Who is it that has made Fred what he is now?是谁把弗雷德培养成现在这样一个人的?
二、表示"……的地方",相当于"the place that..."。如:
1.This is what they call Salt Lake City.这就是他们称作盐湖城的地方。
2.What is now the North Sahara Desert was once a civilized world.
现在是北部撒哈拉沙漠的地方曾是一个文明世界。
三、表示"……的数目",相当于"the amount / number that..."。 如:
1.Our income is now double what it was ten years ago.我们现在的收入是十年前的两倍。
2.The number of the students in our school has reached as many as 20,000, ten times what it was before liberation. 现在我校学生多达2万人,是解放前的十倍。
what的这种特殊含义可以根据句子的意思在翻译时灵活处理,不可千篇一律。再如:
1. Shenzhen is no longer what it was in the past. 深圳不再是过去那样子了。(what=the city that)
2. The color of the flower is different from what it was in the morning.花朵的颜色与早晨的不同。(what=the color that)
很明显, 开头那道高考题的答案what相当于"the time that",表示"……的时间"。另外,what前面的after为介词,并非连词。
巩固练习:
1. She has changed a lot. She's no longer ________she used to be.
A. that B. what C. which D. 不填
2. The tobacco which is used to make cigarettes was first grown in________is now part of the United States.
A. Which B. that C. all D. what
3. No longer______Tom the man______he used to be.
A. will; what B. was; what C. will; that D. is; that
4. What has made China________she is today?
A. that B. what C. as D. which
5. The number of the students of the college has reached 8,000, twice ______ it was when the college was opened ten years ago.
A.what B. as much C. which D. that
答案：BDDBA
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