導語：在學習英語的過程中，我們常常會遇到連線詞that省略的情況。而一旦省略，對同學們的從句識別和判定會帶來一定的困難，從而影響閱讀的理解和翻譯。下面我們就來看一下，三種從句中連線詞that省略用法的幾種情況。
一、that引導定語從句，在從句中充當成分。
1. that在定語從句中作賓語時，往往可省略。如：
(1)John once talked to his mom about the cities (that) he had visited abroad。
在從句中that作visit的`賓語，故可以省略。
(2)The homework (that )I finished last night was left at home。
在從句中that作finish的賓語，故可以省略。
2. that在定語從句中作主語時，不可省略。如：
(1) The teacher that is kind to us goes back home very late every day。
在從句中that作主語，故不可以省略。
(2) My old school that was located in the suburban was razed to the ground。
在從句中that作主語，故不可以省略。
在引導限定性定語從句時，有時相當於in which, at which, for which或on which, 並且在從句中可以省略。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引導名詞性從句時，充當連詞，本身無實際意義。
1. that在引導賓語從句時，通常可省略。如：
We know (that) sound can travel through air。
that引導的從句在主句中充當know的賓語，故為賓語從句，此時that可以省略。
但：(1)在介詞短語後的賓語從句中that常不可省略，且前面往往有個形式賓語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)兩個賓語從句連用時，即使省略了第一個that，也不可省略第二個that。如：
I believe (that) you’ve done your best and that things will get better。
(3)在雙賓語結構中，that從句充當直接賓語或是間接賓語時，不可以省略that。如：
He has told me that he will go to Shanghai tomorrow。
2. that引導主語從句、同位語從句及表語從句時，正規語中，通常不可省略。
(1)We heard the news that our team had won。
that引導同位語從句，that不可以省略。
(2)The fact is that we have lost the game。
that引導表語從句，that不可以省略。
(3)That you didn’t go to the party was a pity.
that引導主語從句，that不可以省略。
不過，如果it作形式主語，that從句放在句末，可以省略that。
(4)It was a pity (that) you didn’t go to the party。
三、that引導狀語從句時，充當連詞，有時也可省略。
1.在結果狀語從句中，that有時可以省略。如：
The sound is so weak (that) you can’t hear it。
總之，that的省略現象在英語學習中很普遍，尤其是在定語從句和賓語從句中，大家遇到這兩種句型時要多加留心that是如何使用的，注意總結。另外，如果大家對that省略的情況把握不好，建議大家在寫作時最好不要省略that。
