1、宾语从句可位于及物动词、介词和某些形容词后。连词that常可省略。介词后一般接疑问词引导的宾语从句。in that(因为),except that(除了),but that(只是)已构成固定搭配，其他介词后一般不接that引导的宾语从句。
I promised that I would change the situation.
All this is different from what American young people would say about friendship.
He is certain that watching so much television is not good for children.
This article is well-written except that it is a bit too long.
2、宾语从句后如有宾补，要用形式宾语it来代替，而把宾语从句移至宾补之后。
He has made it clear that he would not change his mind.
3、在think,believe,suppose,expect等动词后的宾语从句中，如果谓语是否定的，一般将否定词移至主句谓语上，宾语从句则变成肯定形式。
He didn’t think that the money was well spent.
From:https://www.zgghmh.com/CET-4/20000446.asp