eg：We must find out who did all these.

I want to know weather he will come.

I hope that he will come.

① 宾语从句的时态：如果宾语从句前的动词是过去式，则宾语从句的时态应相应变成过去时态；如果宾语从句是客观事实或真理，不管宾语从句前的动词时什么时态，宾语从句都用一般现在时；

eg：The teacher told us that the earth is round.

eg：Todd Park, a local detective, said the method has helped him learn more about an unidentified woman whose skeleton was found near Great Salt Lake.

② 宾语从句后接陈述句，用that引导，则that一般可以省略；

eg：I think that you are right.

③ 宾语从句如果谓语动词是doubt，后面接的一般疑问句通常用weather或if引导；如果前面的谓语动词是don't doubt，则后面从句的连接词一定是that；

eg：I doubt weather he is telling the truth.

I don't that he is telling the truth.

宾语从句如果谓语动词是wonder，句型为I wonder if，后面的连接词不能用weather；

④宾语从句的否定转移：

①think, believe, suppose, expect, fancy, imagine等动词后面宾语从句的否定词转移到主句中，即主句的谓语动词用否定式，而从句的谓语动词用肯定式；

eg：I don't think I know you.

I don' t believe he will come.

②将seem, appear 等后的从句的否定转移到前面。

It doesn't seem that they know where to go.

It doesn't appear that we'll have a sunny day tomorrow.