一、定语从句中that可以省略的情况
1．用作代词，代替前面所指的事物，常见于表示比较关系的状语从句中，例如：
It is warmer in the south than ( that of )the south.
2．引导名词性从句作宾语，即宾语从句，例如：
She said ( that ) she would come.
I suggested ( that )we ( should ) go home.
3．作关系代词，在定语从句中作表语或宾语，例如：
Can I have the records ( that ) I lent you?
He is just the man ( that ) you talked about.
4．在 way （意为 manner ）后面，that 意思为 in which，例如：
Do it the way ( that ) I showed you.
5．在表示个人对事物反应、表示重要性或迫切性的adj后所接的从句中，例如：
I am glad ( that ) you are right.
It is obvious ( that ) they are happy together.
6．so that, so…that, such…that, 结构中，例如：
I came to see you so ( that ) you would know the truth.
She had so many children ( that ) she didn’t know what to do.
I was having such a nice time ( that ) I didn’t to leave.
7．用于表示时间的词后面，整个短语相当于when，例如：
I joined the army the year/month ( that ) my father died.
I thought her nice and honest the first time ( that ) I met her.
= I though her nice and honest when I met her.
8．如果定语从句中的谓语是 there is，作主语的关系代词 that 也常省略，例如：
This is the fastest train ( that ) there is to Beijing.
二、宾语从句用什么引导
连词that,whether,if,
关系代词what,who,whose,which
和关系副词when,where,how,why等.
时态：1·主句用一般现在时,从句可用任意时.
2·主句用过去时,从句用过去某个时态.
3·主句用过去时,从句是真理时,只用一般现在时.
1.宾语从句的连接词
从属连词
连接宾语从句的从属连词主要有that,if,whether连接代词
连接代词主要有who,whom ,whose ,what ,whoever ,whomever ,whosever,whatever,whichever等.
连接代词一般指疑问,但what,whatever除了指疑问外,也可以指陈述.连接副词
连接副词主要有when,where,why,how,whenever,wherever,however等.
2.动词的宾语从句
大多数动词都可以带宾语从句2.动词的宾语从句
大多数动词都可以带宾语从句②有些动词带宾语从句时寻要在宾语与从句前加it
这类动词主要有:hate,take ,owe,have,see to.
3.介词的宾语从句
用wh-类的介词宾语从句
4.形容词的宾语从句
常用来引导宾语从句的形容词有:sure,certain,glad,please,happy,sorry,afraid,satisfied,surprised
5.if,whether在宾语从句中的区别
①if和whether在作“是否”解时,引导宾语从句常放在动词know,ask,care,wonder,find out等之后,介词后一般不用if
②少数动词,如:leave,put,discuss,doubt后的宾语从句常用whether.p分页标题e
③whether后可以加or not,但是if不可以.
④在不定式前只能用whether.
如：I can’t decide whether to stay.我不能决定是否留下.
⑤避免歧异时,我们常用whether而不用if.
