引导宾语从句的that在下列情况下一般不省略：
1. 宾语从句前有插入语。如：
We hope, on the contrary, that he will stay at home with us. 恰恰相反，我们希望他和我们呆在家里。
2. 有间接宾语时。如：
He told me that he was leaving for Japan. 他告诉我他要去日本。
3. that在与之并列的另一个宾语从句之后。如：
He said (that) the book was very interesting and that(不省略) all the children like to read it.他说那本书很有趣，所有小孩都喜欢读。
4. 在“it(形式宾语)+补语”之后时。如：
I think it necessary that he should stay here. 我们认为他有必要留在这里。
5. that从句单独回答问题时。如：
—What did he hear? 他听说了什么事?
—That Kate had passed the exam. (他听说)凯特考试及格了。
6. 在except等介词后。如：
He has no special fault except that he smokes too much.他除了抽烟太多之外,没有什么特别的毛病。
7. 位于句首时。如：
That our team will win, I believe. 我相信我们队会赢。
8. 在较为正式或不常用的动词(如reply, object)后。如：
He replied that he disagreed. 他回答说他不同意。
