主动态表示被动意义
1)一般说来，表示被动意义要用被动态，构成被动态的动词必须是及物动词，不及物动词是没有被动态的。但是，英语里有些不及物动词在SV(A)结构中却含有被动意义，用来表示主语的某种特征、属性。
Enamel wares clean easily. 搪瓷器皿容易弄干净。
This box doesn't close properly. 这箱子关不拢。
These apples cook well. 这些苹果适于烹煮。
This metal cuts easily. 这种金属容易切削。
The pipe does not draw well. 这烟斗不大畅通。
Nylon dries quickly. 尼龙织物干得快。
This material does not dye well. 这料子染不好。
It eats well. 这东西吃上去味道好。
The hall soon filled. 那大厅不久便坐满了人。
Damp Wood will not fire. 潮湿的木头不会着火。
This wheat grinds well. 这种麦子很好磨。
The brake does not grip properly. 刹车不灵。
This car handles well. 这车很好驾驶。
The door won't lock. 门锁不上。
The cow milks well. 这头母牛出奶率高。
These books pack easily. 这些书易于包装。
These potatoes peel easily. 这些土豆皮很容易剥。
His new novel is selling well. 他的新小说销路良好。
The window won't shut. 这窗关不上。
Some kinds of wood split easily. 有些木材容易劈开。
Some kinds of food soon spoil. 有些食物很容易变坏。
This linen c1oth spots easily. 这麻布容易沾污。
White clothes stain easily. 白色衣服容易弄脏。
The damp match won't strike. 这潮湿的火柴擦不着。
This paper tears easily. 这种纸一撕就破。
Not every idiom translates with such ease. 不是每个习语都能这样容易地译出来。
The cloth washes well. 这布很耐洗。
This material won't wear. 这种材料不耐久。
The door won't open. 这门打不开。
从以上的例子可以看出，句中的谓语动词具有下面的三个特点之一：谓语动词用否定式;动词之后有副词或小品词;动词之后有形容词或介词短语。
2)当 need, want, require, be worth后面接doing时，表示的是被动意义。
The door needs repairing.= The door needs to be repaired. 门该修了。
This book is worth reading. 这本书值得一读。
Your hair wants cutting. 你的头发该理了。
The floor requires washing. = The floor requires to be washed.地板需要冲洗。
带宾语分句的句子转换成被动态
带宾语分句(主要是that分句)的句子可以转换为两种被动句型。
【例如】
People think that she is honest. (a)
→ It is thought that she is honest. (b)
→ She is thought to be honest. (c)
(b) 以it作形式主语，将(a)中的动词变为被动态，保留(a)中的that分句;(c)将分句的主语变成被动句中的主语，将(a)中的动词变为被动态，再将(a)中的that分句改为不定式短语，放在被动态后面。能这样用的动词主要有：think, consider, assume, suppose, say, report, acknowledge, feel, believe, find, presume, know, understand, etc.
如果that分句的动词是进行体，这时分句要改为不定式进行体。
They suppose that she is coming.
→ It is supposed that she is coming.
→ She is supposed to be coming.
They supposed that she was coming.
→ It was supposed that she was coming.
→ She was supposed to be coming.
如果that分句的动作或状态发生在主句之前，这时分句要改为不定式完成体。
People feel that little was done to prevent the accident
→ It is felt that little was done to prevent the accident.
→ Little is felt to have been done to prevent the accident.
They report that both sides have reached an agreement.
→ It is reported that both sides have reached an agreement.
→ Both sides are reported to have reached an agreement.
People think that she was honest.
→ It is thought that she was honest.
→ She is thought to have been honest.
短语动词的被动语态
短语动词通常被视为一个整体，转化为被动语态时，词组内的介词、副词、名词等不能拆散或省略。
The old house will be pulled down tomorrow.
The little boy was made use of by the drug-pusher to carry drugs for him.
That sort of thing should be done away with.
The sports meet is to be put off.
另外，有些短语动词不能用被动语态，如：take place, look like, belong to, depend on, consist of, agree with等。
The accident took place yesterday on the expressway.
He looks like an old man.
The honor belongs to us.
He is the person to depend on.
From:https://www.zgghmh.com/CET-4/20000693.asp