在考研英语长句阅读中，我们常常会遇到连接词that省略的情况。而一旦省略，对同学们的从句识别和判定会带来一定的困难，从而影响阅读的理解和翻译。本文我们就来看一下，三种从句中连接词that省略用法的几种情况。

一、that引导定语从句，在从句中充当成分。

1. that在定语从句中作宾语时，往往可省略。如：

(1)John once talked to his mom about the cities (that) he had visited abroad。

在从句中that作visit的宾语，故可以省略。

(2)The homework (that )I finished last night was left at home。

在从句中that作finish的宾语，故可以省略。

2. that在定语从句中作主语时，不可省略。如：

(1) The teacher that is kind to us goes back home very late every day。

在从句中that作主语，故不可以省略。

(2) My old school that was located in the suburban was razed to the ground。

在从句中that作主语，故不可以省略。

3.that在引导限定性定语从句时，有时相当于in which, at which, for which或on which, 并且在从句中可以省略。如：

(1)Attitudes towards daydreaming are changing in much the same way (that ) (in which) attitudes towards night dreaming have changed。

(2)I like the music for the very reason (that ) (for which) he dislike it。

(3)We arrived the day (that ) (on which) they left。

二、that引导名词性从句时，充当连词，本身无实际意义。

1. that在引导宾语从句时，通常可省略。如：

We know (that) sound can travel through air。

that引导的从句在主句中充当know的宾语，故为宾语从句，此时that可以省略。教育学考研参考书

但：(1)在介词短语后的宾语从句中that常不可省略，且前面往往有个形式宾语it。如：

You may depend on it that they will support your plan。

See to it that you arrive at the railway station on time。

(2)两个宾语从句连用时，即使省略了第一个that，也不可省略第二个that。如：

I believe (that) you’ve done your best and that things will get better。

(3)在双宾语结构中，that从句充当直接宾语或是间接宾语时，不可以省略that。如：

He has told me that he will go to Shanghai tomorrow。

2. that引导主语从句、同位语从句及表语从句时，正规语中，通常不可省略。

(1)We heard the news that our team had won。

that引导同位语从句，that不可以省略。

(2)The fact is that we have lost the game。

that引导表语从句，that不可以省略。

(3)That you didn’t go to the party was a pity. 

that引导主语从句，that不可以省略。

不过，如果it作形式主语，that从句放在句末，可以省略that。如：

(4)It was a pity (that) you didn’t go to the party。

三、that引导状语从句时，充当连词，有时也可省略。

1.在结果状语从句中，that有时可以省略。如：

The sound is so weak (that) you can’t hear it。

总之，that的省略现象在英语学习中很普遍，尤其是在定语从句和宾语从句中，大家遇到这两种句型时要多加留心that是如何使用的，注意总结。另外，如果大家对that省略的情况把握不好，建议大家在写作时最好不要省略that。