一，完成时的主动与被动形式
1 首先我们要明确一下主动的 完成时 是什么格式
have + done/cleaned /seen等
Somebody should have cleaned the room.
某人早就应该打扫这间屋子了
知识点小补充 : should have done 表示“过去本应该做某事却没做”，
根据被动语态的一般形式，我们可以推导出来 ，完成时的被动形式加上be 动词
have been + done /cleaned /seen 等
The room should have been cleaned.
这间屋子早就应该被打扫了
2 现在完成时
强调动作的完成性，讲述现在的情况。
还是先看主动语态：
have / has + done 等
The room lookes nice .Somebody has cleaned it .
房间看起来很好，某人已经打扫它了。
被动：
have / has been + done 等
The room looks nice .It has been cleaned .
这房间看起来不错，他已经被打扫过了。
3 过去完成时
谈论的是一个事情发生之前的动作或者行为，
had done ——> 过去——>现在
When Sarah arrived at the party ,Pual had already gone home .
在赛瑞到这个聚会时（过去时），皮尔已经回家了。
主动语态 had + done
The room looked nice .Somebody had cleaned it .
被动语态 ： had been + done
The room looked nice .It had been cleaned .
4 现在进行时
表示现在正在进行的动作（该动作还没有完成），或者某一阶段正在进行的动作，变化。
主动 am /is /are +(do)ing
Somebody is cleaning the room at the moment .
有人正在打扫房间
被动 ：am / is / are + being ( done )
The room is being cleaned at the moment .
房间目前正在被打扫
5 过去进行时
表示过去某个时间某人正在进行的动作，这个动作在这个时间点之前已经开始了，还没有结束。
started doing (过去)——>was doing ——>finishied doing (过去)——>现在
主动：was/ were + do(ing)
Somebody was cleaning the room when i arrived .
当我到达的时候，某人正在打扫房间。
被动 : was / were + being (done )
The room was being cleaned when i arrived.
我到的时候，房间正在被打扫。
