句式结构的转换

从教多年，我经常见到学生们由于句式结构理解上的模糊导致在考试中不必要的失分。掌握基本的句式结构，了解不同结构之间转换的规律就显得尤为必要。

英语的基本句子结构主要是五种。即1.主、系、表；2.主、谓；3.主、谓、宾；4.主、谓、宾、宾；5.主、谓、宾、宾补等。试看下列例句：

1.主语+系动词+表语

①Alice seems interested in English.

②Tom is good at playing basketball.

③The soup tastes good.

2.主语+谓语

①Mr. Zhou, an English teacher, works hard.

②His brother gets up very early every morning.

③The old man died last week.

3.主语+谓语+宾语

①We live a happy life.

②Bob likes playing basketball.

③Mary has a large collection of stamps.

4.主语+谓语+间接宾语+直接宾语

①Mr Green often tells us many interesting stories.

②My mother bought me a new coat this morning.

③Our English teacher gave us much advice on how to learn English.

5.主语+谓语+宾语+宾语补足语

①We call the boy a little angel.

②The news made all the students happy.

③He found the house broken into last week.

在以上五种句式结构中，主语、宾语、表语、同位语包括宾语补足语等成分都出现了用名词充当的现象。其中主语、宾语、表语、同位语均可用从句来充当，这四大从句可以统称为名词性从句。

试看下列例句（括号内是整句句式结构类型）

1.主语从句

①What he said was right. (主、系、表)

(主语从句)

②That he will come makes us happy. (主、谓、宾、宾补)

(主语从句)

③It is clear that he will buy the car. (主、系、表)

(形式主语) (主语从句)

2.宾语从句

①We all know that the earth is round. (主、谓、宾)

（宾语从句）

②I think (that) we should buy the computer. (主、谓、宾)

（宾语从句）

③The students hope that they will have a school bus soon. (主、谓、宾)

（宾语从句）

3.表语从句

①The news is that he himself will attend the meeting.(主、系、表)

（表语从句）

②The problem is which bike I should take.(主、系、表)

（表语从句）

③This village is where I was born. (主、系、表)

（表语从句）

4.同位语从句

①The news that he will visit America makes us excited. （主、谓、宾 、宾补） （同位语从句）

②The fact that he is a good teacher is obvious. (主、系、表) （同位语从句）

③She has no idea how she should solve the problem. (主、谓、宾) （同位语从句）

根据以上内容，我们可以看出，从句充当的成分是可以转变的。试看下面的句式变化的关系。设x是一个完整的句子，拥有五大基本句型中的任意结构（例如：The earth is round），则可得：

1.We all know that x.

把划线部分看成整体，将上句转成被动语态，则得

2.That x is known to us all.

由于 that x 充当主语成分，可能是很长的成分，为了达成句子平衡，可使用形式主语it, 即：

3.It is known to us all that x.

同样地，我们也可以用从句充当表语和同位语而形成表语从句和同位语从句，即：

4.The fact is that x . (表语从句)

5.We all know the fact that x. （同位语从句）

另外，我们在定语从句中，还可能使用整个句子表示一个事实，此时非限制性定语从句没有明确的先行词，而是修饰前面的整个句子，即：

6.x, as we all know.

在上句中，as 引导的从句也可以调整到句首，即：

7.As we all know, x.

将上两句的定语从句部分变成被动语态则可得：

8.x, as is known to us all.

9.As is known to us all, x.

另外，在常见的名词性从句中，what是一个活跃的成分，结合以上各句，我们可以得到：

10.What we all know is that x.

11.What is known to us all is that x.

综上所述，从句间的类型是可以转换的。

我们比较其中的3、9、11三句，它们代表着三个不同的句子类型，但很容易混淆，应引起考生的注意。为了起到巩固的作用，试完成下列选择题：

1. _______ we all know, Guilin is a beautiful city.

A. What B. That C. As D. Which

2. _______ is reported in China Daily, a famous newspaper, Ding Junhui has won the game.

A. It B. What C. As D. That

3. _______ is believed by many people is that the grass can be used to cure cancer.

A. It B. What C. As D. That

4. _______ is suggested by Bai Yansong, a famous journalist, that the Chinese government should pay more attention to environmental protection.

A. That B. What C. It D. As

5. I can’t believe the news ________ he has won the game.

A. which B. what C. that D. as

6. The news ________ he will come back makes us happy.

A. which B. what C. that D. as

7. ________ is often the case, some students can’t write articles well though they have a large vocabulary.

A. That B. What C. It D. As

8. No one knew ________ the professor said meant.

A. that what B. it what

C. what that D. what what

(参考答案：1. C 2. C 3. B 4. C 5. C 6. C 7. D 8. D)

从句的转换一直是高考的重、难点，也是我们看懂完形填空、阅读理解及任务型阅读中的复杂结构所必备的技巧，所以应引起考生的重视。以上浅述，仅为管窥之见，浅陋难免，敬请指正。

（作者单位：江苏省泰兴中学）