宾语从句转化为简单句的几种情况，具体解析如下：

1.若主句主语与从句主语一致，而主句的谓语动词为hope/decide/ wish/choose/agree/ promise等，则从句可简化为不定式

I hope that I will succeed. 

我希望我会成功。

→ I hope to succeed.

I have decided that I will accept the offer. 

我已经决定接受邀请。

→I have decided to accept the offer.

She promised that she would be back. 

她承诺她会回来。

→She promised to be back.

2.若主句主语与从句主语一致， 而从句的引导词为代词（如who, what）或副词（如when, where, how）等时，则从句可简化为“疑问词+不定式”

She knows what she should do next. 

她知道接下来她该做些什么。

→She knows what to do next.

She knew where she would live. 

她知道她将住在哪里。

→She knew where to live.

He remembers how he can open the door. 

他记得该如何开门。

→He remembers how to open the door.

注：若主句的谓语动词接双宾语，且从句主语与间接宾语所指一致，该宾语从句也可简化为“疑问词+不定式”

Could you tell me how I can win the contest? 

请告诉我，我该如何赢得比赛？

→Could you tell me how to win the contest?

Have you taught her what she should do? 

你已经教她该做些什么了吗？

→Have you taught her what to do?

3.若主句主语与从句主语不同，而主句的谓语动词为order/require等，则从句可简化为“名词/代词+不定式”

The commander ordered that we should set out at once. 

指挥官命令我们马上出发。

→The commander ordered us to set out at once.

They require that I should be there. 

他们要求我要在那里。

→They require me to be there.

4.某些动词后的宾语从句可简化为“it + 形容词 + 不定式短语”

She thinks that it is important to finish the homework. 

她认为完成作业很重要。

→She thinks it important to finish the homework.

He found that it was difficult to convince her.

他觉得难以让她信服。

→He found it difficult to convince her.

5.某些宾语从句可改为名词短语

He doesn’t understand what she says. 

他不明白她说的话。

→He doesn’t understand her words.

He has told me how I can get to the station. 

他已告诉我该怎么去车站。

→He has told me the way to the station.

She doesn’t know when she was born. 

她不知道她什么时候出生的。

→She doesn’t know the time of her birth.

6.某些动词后的宾语从句可简化为“宾语+动词-ing”

She found that there was a dog lying on the ground. 

她发现一只狗躺在地上。

→She found a dog lying on the ground.

She saw that the dogs were running after a rabbit. 

她看到狗在追一只兔子。

→She saw the dogs running after a rabbit.

7.主句主语与从句主语一致时，某些动词后的宾语从句可简化为“动词-ing”形式的简单句

I remember that I have closed the door. 

我记得我已经关了门。

→I remember closing the door. 

She forgets that she has called him. 

她忘记她已经打过电话给她。

→She forgets calling him.

8.某些宾语从句可改为含过去分词或过去分词短语的简单句

She found that the road was covered with fallen leaves.

她发现路被落叶覆盖了。 

→She found the road covered with fallen leaves.

The detective found that the man was killed in bed.

侦探发现这男士在床上被杀。

→The detective found the man killed in bed.

以上就是宾语从句转化为简单句的几种情况，希望对你有所帮助。