有这个说法
（1）现在分词的主动语态：现在分词主动语态的一般式表示与谓语动词所表示的动作同时发生,完成
式表示的动作在谓语动词所表示的动作之前发生,常作状语.例如：
They went to the park, singing and talking. 他们边唱边说向公园走去.
Having done his homework, he played basket-ball. 做完作业,他开始打篮球.
（2）现在分词的被动语态：一般式表示与谓语动词同时发生的被动的动作,完成式表示发生在谓语动
词之前的被动的动作.
The problem being discussed is very important. 正在被讨论的问题很重要.
Having been told many times, the naughty boy made the same mistake.
被告诉了好几遍,这个淘气的孩子又犯了同一个错误.
（1）一般式：不定式的一般式所表示的动作与谓语动词动作同时发生或发生在谓语动词动作之后,
例如：
I'm glad to meet you.
He seems to know a lot.
We plan to pay a visit.
He wants to be an artist.
The patient asked to be operated on at once.
The teacher ordered the work to be done.
（2）进行式：不定式的进行式所表示的动作与谓语动词动作同时发生,例如：
The boy pretended to be working hard.
He seems to be reading in his room.
（3）完成式：不定式的完成式表示的动作发生在谓语动词动作之前,例如：
I regretted to have told a lie.
I happened to have seen the film.
He is pleased to have met his friend.