语态
语态是动词的一种形式，表示主语和谓语动词之间的具体关系，分为 主动 语态和 被动 语态。 主动 语态表示主语时谓语动词所表示的动作的执行者， 被动 语态表示主语时谓语动词所表示的动作的承受者。
- 被动语态基本形式：
be（任何形式）+ done by + ······
常见时态的被动语态形式
| 时间\状态 | 一般 | 进行 | 完成 |
|---|---|---|---|
| 现在 | am/is/are + done | am/is/are + being done | have/has been + done |
| 过去 | was/were + done | was/were + being done | had been + done |
| 将来 | will be + done will + 动原 |
will be being done | will have + been done |
带情态动词的被动语态结构：情态动词 + be done
常见的情态动词：can/could, will/would, may/might, should, must
现在分词作宾补，变被动语态时，现在分词不变。
–I caught the boy playing games.
–The boy was caught playing games.
–I saw them taking photos.
–They were seen taking photos.
⚠️注意：主动语态中宾补省略to，被动语态中不能省略。
let/make/have/see/watch/notice/feel/hear/observe ➕ sb./sth. ➕ 动原
变被动语态为：
sb./sth. ➕ be let/made/had/seen/watched/noticed/felt/heard/observed ➕ to 动原
主动形式表达被动意义
1. sth. nedd/want/require/deserve doing
2. sth. be worth doing
eg. The room needs cleaning.
eg. The movie is worth watching.
⚠️注意：need/want/require/deserve/be worth + doing:用动名词的主动形式表示被动意义，器含义相当于动词不定式的被动形式。
半系动词，在系表结构中用主动形式表达被动意义
feel, sound, taste, look, smell, prove, remain, seem
列：The soup smells good. (汤闻起来很不错。)
The snow feels very cold. (雪摸起来很冷。)
某些表示主语（指物）本身的内在品质或所具有的性能的词，常与well，easily，badly，smoothly等副词一起连用。
cut, read, sell, wear, write, lock, shut, open, wash, clean, burn
This pen writes smoothly.
Her novel sells well.
sth./sb.＋系动词＋todo”结构（如：sb.is to blame）
主要用于sth. be to rent; sb. be to blame 等
The taxi is to rent.这个车是出租的。
The house is to let.此房出租。
She is to blame.她应当受到谴责。
Mr.Green stood up in defense of the 16-year-old boy, saying that he was not the one___.
A. blamed B. blaming C. to blame D. to be blamed
不能用于被动语态的动词及动词短语
不及物动词不能用于被动语态，常见的有：appear, die, happen, occur, take, place, come ture, break out, lie(躺；位于), remain表示 “状态” 的谓语动词不能用于被动语态：last, hold(坚持), consist of, benefit, contain, equal, fit, join, mean, look like表示 “归属” 的动词不能用被动语态：have, own, belong to
I belong to you.(我属于你。)表示 “希望、意图” 动词不能用于被动语态：wish, want, hope, like, love, hate