难点之七：连接词that 引导名词性从句时的省略与保留。 连接词that 引导名词性从句时，有时可以省略，有时不能省略，有时两者兼可。注意以下几种情形： （1） that引导宾语从句时，在口语中常被省略。但是下列情况下that应保留：
① 当主从句之间有时间等状语或插入语时；② that引导两个或者两个以上的宾语从句时，第二个或第二个以上的宾语从句的that不宜省略；③ 如果宾语从句中含有if 等引导的主从复合句时， that一般不能省略；④ 宾语从句提前时，that一般不能省略；⑤ 简略答语中的宾语从句，that不宜省略；⑥ 当it做形式宾语代替that引导的宾语从句时，that一般不宜省略。
（2） 引导主语从句的that位于句首时不能省略（但用it做形式主语，that从句后移，此时that可以省略）；
（3） 引导表语从句的that一般不能省略；
（4） 引导同位语从句的that不能省略。
【经典考例】
① It has been proved eating vegetables in childhood helps to protect you against serious illnesses in later life. （2008上海卷）
A. if B. because C. when D. that
② News came from the school office Wang Lin had been admitted to Beijing University. （2009四川卷）
A. which B. what C. that D. where
考点释疑 题目① it是形式主语，that从句是真正主语（此时that可以省略），故选D；题目② that引导分隔同位语从句，that不能省略，故选C。
难点之八：主语是reason时，后面表语从句连接词的使用问题。
根据英语惯用法，“the reason for... ”或“the reason why... ”在句中做主语时，其后的表语从句一般不用because引导，而用that引导。如：
The reason why he was late was that his mother was ill. 他迟到的原因是因为他的母亲病了。
但是，在现代英语中，特别是在口语或者非正式文体中，也常见到用because引导表语从句的情形。如：
The reason why he is late is that（或because） there was a breakdown on the railway. 他迟到的原因是因为铁路出了问题。
按照传统语法，“the reason... is because... ”句型是错误的，应将because改为that。但是近些年来，句型“the reason... is because... ”不仅在口语中，而且在书面语中也较为常见了，甚至还得到了某些词典的认可。但尽管如此，在比较规范的考试中，作为考生，我们还是要尽量避免使用这个表达，而严格按照传统的句型来处理相关问题。
温馨提示：如果主语是it， that 或this时，可以用because或why引导表语从句。It（That / This） + be +because... 意为“这是因为……”或“这是由于……的缘故”；It（That / This） + be +why... 意为“这就是……的原因”。如：
That was because he fell ill. 这是因为他病倒了。
That was why he fell ill. 这就是他病倒的原因。
【经典考例】
① Part of the reason Charles Dickens loved his own novel， David Copperfield， was it was rather closely modeled on his own life. （2010北京卷）
A. what B. that C. why D. whether
② I was very late for school this morning. That’s I stayed up too late last night.
A. why B. when C. because D. how
考点释疑 题目①，主语是reason，其后的表语从句应用that引导，故选B；题目②结合语境和句意可知，后面分句表达的应该是“这是因为我昨天晚上熬夜太晚了”，因此用because引导表语从句，故选C。
难点之九：双重疑问句（或复杂疑问句）句型用法。
所谓“双重疑问句（或复杂疑问句）句型”就是“特殊疑问词+do you think （believe， guess， suppose， imagine， propose， say， hope... ）+ （从句主语） + 从句谓语 + 其他成分”句型。这种句型常用来征询对某一问题的看法、认识、推测、判断或希望等。这种双重疑问句的主句属于特殊疑问句句型，宾语也是由宾语从句充当的，但是它没有引导词，前面主句的特殊疑问词在逻辑上应该是宾语从句的一部分。如：
Why do you think he is so sad？ 你认为他为何这么伤心？（注意句子语序）
Who do you guess let the dog out？ 你猜是谁把狗放出去的？ 【经典考例】
Mum is coming. What present for your birthday？
A. you expect she has got B. you expect has she got
C. do you expect she has got D. do you expect has she got
考点释疑 C。考查的是双重疑问句句型。解答这类试题时，要特别注意语序问题。
难点之十：suggest和insist后宾语从句中的谓语动词的语气问题。
根据英语习惯用法，当suggest意为“建议，提议”解时，后接that引导的宾语从句中谓语动词常用虚拟语气，即“should+动词原形”，should可以省略；作“暗示，表明，使人想到（或想起）”解时，后接that引导的宾语从句中谓语动词常用陈述语气；insist 作“坚持认为，坚持说”时，其后由that引导的的宾语从句中动词用陈述语气；作“坚持要求”解时，其后由that引导的的宾语从句中动词用虚拟语气，即“should+动词原形”，should可以省略。
【经典考例】
I insist that a doctor immediately.
A. has been sent for B. sends for C. will be sent for D. be sent for
考点释疑 题意为“我坚持要求立即派人去请医生”，insist意为“坚持要求”，所以从句中动词用虚拟语气。又因为“a doctor”与“send for”之间时逻辑上的被动关系，故应用被动式，正确答案为D。此处“be sent for”是“should be sent for”的省略形式。
巩固练习
1. the rising house prices will be under control is what worries people most.
A. What B. Whether C. That D. If
2. She is very dear to us. We have been prepared to do it takes to save her life.
A. whichever B. however C. whatever D. whoever
3. made the school proud was more than 90% of the students had been admitted.
A. What； because B. What； that C. That； what D. That； because
4. The other day， my brother drove his car down the street at I thought was a dangerous speed.
A. as B. which C. what D. that
5. The suit fitted him well the color was a little brighter.
A. except for B. except that C. except when D. besides
6. is known to us all is that the 2012 Summer Olympic Games will take place in London.
A. It B. What C. As D. That
7. A wonderful idea suddenly occurred to me I would turn to the reference book to finish my homework.
A. that B. if C. when D. which
8. Great honors will be given to has successfully rescued the victims of the earthquake.
A. those who B. whoever C. no matter who D. whom
9. It makes his life quite different he has received higher education abroad.
A. that B. which C. what D. how
10. The policy of the mainland is very clear and straightforward， and the key problem is the leaders of Taiwan will accept it.
A. that B. how C. why D. whether
11. Many people firmly believed a healthy lifestyle can improve the quality of life.
A. that B. if C. how D. why
12. Many experts believe that teachers’ development is the key to better education lies.
A. that B. what C. where D. which
13. Sorry I’m late， but you cannot imagine great trouble I took to find your house.
A. how B. however C. whatever D. what
14. Faced with challenges， you should believe your courage is makes a difference.
A. that B. what C. which D. whatever
15. Evidence has been piled up drinking water after getting up in the morning contributes to one’s health.
A. what B. which C. if D. that