第一种情况
连词that很少用来引导原因状语从句，但在某些表示情感的不及物动词之后，that 分句说明这种情感产生的原因，因而可以看作原因状语分句。例如：
I rejoice that you are coming home. 你要回家我很高兴。
I grieve that he has lost his dear child. 他失去了孩子我很悲伤。

第二种情况
在以表示情感状态的形容词为主语补语的SVC结构中，that-分句也可以看作原因状语分句，表示这种感情所产生的原因。例如：
I am pleased that you have decided to come.
I am sorry (that) I broke your pen.
I am ashamed that you should be so cowardly.
I was surprised that he disagreed.

第三种情况
在not that… but that…结构中，that=because，从而这种that-分句也是原因状语。
I haven’t finished writing the report yet, not that I dislike the work, but that I have not time.
He always travelled third-class, not that he was so miserly, but that he wanted to go side by side with ordinary people.

第四种情况
在下列结构中，that=as，它所引导的分句有时表示原因，有时表示让步：
Coward that he was, he ran away as soon as the enemy attacked. (表原因)
Coward that he was, he ran forward at the signal to attack. （表让步）