一、一般现在时

主动句：

Tom writes letters every day.

被动句：Letters are written by Tom every day.

含双宾语：

The company provided the employees with training.

被动句：Training was provided to the employees by the company.

二、一般过去时

主动句：

They completed the project last month.

被动句：The project was completed last month.

含双宾语：

She gave the gift to her friend.

被动句：The gift was given to her friend by her.

三、一般将来时

主动句：

We will launch the new product next quarter.

被动句：The new product will be launched next quarter.

四、现在进行时

主动句：

The chef is preparing dinner right now.

被动句：Dinner is being prepared by the chef right now.

五、过去进行时

主动句：

They were painting the house when I arrived.

被动句：The house was being painted when I arrived.

六、现在完成时

主动句：

She has finished her homework already.

被动句：Her homework has been finished already.

七、过去完成时

主动句：

By the time we arrived, the meeting had started.

被动句：The meeting had been started by the time we arrived.

八、特殊动词（不及物动词）

注意：部分动词（如 run, laugh, eat）为不及物动词，无法直接转为被动语态。 主动句：He runs every morning.

被动句：This morning was run by him.

总结

将主动句转换为被动句时，需注意：

将宾语变为主语；

动词改为过去分词；

时态需保持一致。通过这些规则，可灵活处理不同语境下的句式转换。