Passives 被动语态

Passives
We make the passive using ‘be’ – in a suitable tense – and the past participle (‘done’, ‘played’ etc.). We use the passive:
我们形成被动语态的时候要加上be动词，be动词要根据上下文选择时态，然后加上过去分词(‘done’, ‘played’ 等)，在以下情况下使用被动语态：

1) … when we don’t know, or we are not interested in, who does an action. 当我们不知道或者我们不在乎谁做了该动作，可以用被动语态。
• My car was stolen yesterday.
We don’t know who stole the car.
• A lot of wine is produced in France.
It’s not important who produces the wine.

2) … when the main topic of the sentence isn’t who did the action. 当句子的主题不是谁做了该动作。
• Television was invented in the 1920s by John Logie Baird.
The main topic here is television – we aren’t particularly interested in ‘who’.
• Kennedy was assassinated in 1963.
In English we tend to put the most important thing at the start of the sentence. 在英语里，我们总是把最重要的事情放在句子的开头。

3) … more in written English than in spoken English. 在书面英语里面出现得比口语更多。
• War and Peace was written by Tolstoy.
You often see the passive in textbooks. 你经常在教科书中看到被动语态。
• The mixture is heated to 500˚C.
Scientific texts especially use the passive.
科学类文章特别喜欢用被动语态。

Tenses 时态

The passive can be used with all tenses - the form of ‘be’ changes.
被动语态适用于所有时态中—通过改变be动词形式来决定时态。
• What is tiramisu made from?. Present Simple.
• The hall is being painted this week so our class will be in a different room. Present Continuous.
• Oranges have been grown here for centuries. Present Perfect.
• When he got home he found that his flat had been burgled. Past Perfect.
• The work won’t be finished until next week. Future Simple.

Modal verbs also use ‘be’ and the past participle. 情态动词同样使用be动词和过去分词。

• Answers must be written in pencil.
• Competition entrants might be chosen to appear on TV.