We make the passive using ‘be’ and the past participle (‘done’, ‘played’ etc.). We use the passive:
1. When we don’t know, or we are not interested in, who does an action. 实施的人不重要或者我们不感兴趣 In the past, new words were coined. We don’t know who invented the words.
English is used in education, in science and in business. It’s not important who uses English in these contexts.
2. When the main topic of the sentence isn’t the person who did the action. 把主要的东西放在开头 The word ‘robot’ was coined in the 1920s by the writer Karel Čapek. The main topic here is the word ‘robot’, not the person who invented it.
In English we tend to put the most important thing at the start of the sentence.
The passive can be used with all tenses. We change the form of ‘be’. Shakespeare’s plays are performed all over the world.
3. When we want to add variety to our language, we can mix passives with actives. 可以主动被动交替使用，增加语言的多样性