名词性从句难点突破

名词性从句难点突破
一、that在宾语从句中不可省略的情况
宾语从句的引导词that在口语中常常省略，但在下列情况中，that应保留。

1. 当主、从句之间有时间等状语时，that不能省略，否则会产生歧义。

如：
She said last night that she did some reading.
She said last night she did some reading. (last night可理解为修饰said或did some reading，因此产生歧义)
2. 主、从句之间有插入语时不可省去that。

如：
I don’t doubt, in any case, that our school team will win the match.
3. 引导两个或两个以上的宾语从句时，第二个以及第二个以后的宾语从句中的that不能省略。

如：
Maria promised that she would come and see him sometimes, and that she would never forget him.
4. 如果宾语从句中含有主从复合句，that一般不省略。

如：
They promised me that if I worked hard from then on, they would buy me a computer.
5. 宾语从句提前时，that一般不宜省略。

如：
That Bob was really frightened , I can’t believe.
6. 简短回答中的宾语从句不宜省略that。

如：
—What do you assume from his attitude?
—That he was frightened.
7. 当it作形式宾语代替that引导的宾语从句时，一般保留that。

如：
I found it quite a surprise that everybody in that city has a car.
二、同位语从句与定语从句的区别
1. that引导的定语从句与同位语从句的区别
1) that引导同位语从句时，不充当从句的任何成分；但它引导定语从句时，充当定语从句的成分。

如： The fact that the seawater cannot be used for drinking is known to all. (that在从句中不充当任何成分，引导的是同位语从句)
This is the fact that you must know clearly. (that在从句中作动词know的宾语，引导定语从句)
2) that引导的同位语从句与它所说明的名词之间是同位关系，说明名词的具体内容，且该名词只限于抽象名词；而that引导的定语从句与先行词是从属关系，说明先行词的性质特征，先行词无范围限制。

2. when, where, why引导的同位语从句与定语从句的区别
当when, where等引导同位语从句时，表达疑问意义，引导词与被同位的词没有意义上的联系；引导定语
从句时，其意义与先行词基本相同，无疑问意义。

它们引导两种从句时，都在从句中作状语。

如：
Then arose the question where we were to get the machines needed.
(where与question没有意义上的联系，where意为“哪儿”，引导的是同位语从句)
I still remember the day when I first came to Beijing. (when相当于on the day，无疑问意义，引导定语从句)。