一、用于引導(dǎo)主語從句
在許多情況下，當(dāng)語義上需要用一個(gè)較復(fù)雜的that從句用主語時(shí)，若直接將其置于句首位置，則會(huì)顯得“頭輕腳重”。這時(shí)，我們通常采用的辦法便是使用形式主語it來改變句子結(jié)構(gòu)。如：
That he had no girl friends worried his parents a lot.= It worried his parents a lot that he had no girl friends. 他沒有女朋友，這件事使他父母非常不安。
That he has fully recovered makes me feel good.=It makes me feel good that he has fully recovered. 他已痊愈，真令我高興。
That he had not said anything surprised everybody.=It surprised everybody that he had not said anything. 他一言不發(fā)，這使大家很吃驚。
在比較正式的文體中，有時(shí)也可借助the fact這一輔助手段，按以下方式改寫句子：
The fact that he had no girl friends worried his parents a lot.
The fact that he has fully recovered makes me feel good.
The fact that he had not said anything surprised everybody.
二、用于介詞后引導(dǎo)賓語從句
按英語習(xí)慣，介詞后面通常不能直接跟一個(gè)that從句作賓語，遇此情況，人們通常在that從句前使用the fact。這樣一來，就變成了the fact用作介詞的賓語，而其后的that從句則成了the fact的同位語從句。如：
They were worried over the fact that you were sick. 他們?yōu)槟闵“l(fā)愁。
I didn’t go out because of the fact that it was raining. 因?yàn)樵谙掠辏晕覜]出去。
Were it not for the fact that you helped me, I would be homeless. 若非你的幫助，我仍會(huì)無家可歸。
He must face up to the fact that he is no longer young. 他必須勇于正視自己不再年輕這一事實(shí)。
It’s time you woke up to the fact that you’re not very popular. 你早就該明白你不怎么受歡迎了。
The judge paid a lot of attention to the fact that the child was unhappy at home. 法官非常注意這一情況，即孩子在家里并不快樂。
He said the parents were responsible for the fact that the child had run away. 他說孩子父母應(yīng)對(duì)孩子逃跑一事負(fù)責(zé)。
注：英語中只有極個(gè)別介詞(如except等)可直接跟that從句。如：
The two books are the same except that this one has an answer key at the back. 除了這本書后面有問題答案以外, 這兩本書完全一樣。
三、用于動(dòng)詞后引導(dǎo)賓語從句
英語中有的動(dòng)詞雖為及物動(dòng)詞，可接名詞或代詞作賓語，但通常不接that從句作賓語。若語義上需要接一個(gè)that從句，則可借助the fact結(jié)構(gòu)。如：
I dislike the fact that he smokes. 我厭惡他吸煙。
No one can deny the fact that fire burns. 無人能否認(rèn)火能燃燒的事實(shí)。
You can’t escape the fact that she has got married three times. 她結(jié)過三次婚，這個(gè)事實(shí)你是不能逃避的。
We must face the fact that we might lose our deposit. 我們必須正視我們可能失去存款這一事實(shí)。
I admired the fact that he would talk to students outside the classroom or talk with them on the telephone. 我羨慕他經(jīng)常在課外與學(xué)生聊天或通過電話與學(xué)生聊天。
