主动形式表被动
主语是物、形式是主动，但意思是被动：说明主语本身的性能或特点。
The book sells well. ／ Your coat needs cleaning.
要点
- sell / write / read / wash / clean / cook / keep / wear 与 well / easily / smoothly 连用，说明主语性能：This kind of cloth washes well.
- 这类句子不用被动、也不用进行时：The book sells well（不写 is sold well / is selling well）。
- need / want / require + doing = need to be done：My hair needs cutting. = My hair needs to be cut.
- open / close / begin / finish / happen 等可作不及物动词表被动意义：The shop opens at nine.
- look / sound / taste / smell / feel 等系动词本身不表被动：The soup tastes delicious.（没有 is tasted）
- 这一族的成立要看有没有那个副词顶着：This kind of cloth washes well. —— 若没有 well / easily 这类词、说的只是某一次真被洗了，就得回被动（The cloth was washed yesterday.）。
- deserve 也走 need doing 那一条：His advice deserves thinking about. —— 判它能不能这样用，看换成了 to be done 之后意思变不变（deserves to be thought about 照样成立）。
例句
These pencils sell very well in our shop.
这种铅笔在我们店里很畅销。
The new book reads easily and I can't put it down.
这本新书读起来很轻松，我爱不释手。
Your coat needs cleaning. It is too dirty.
你的外套该洗了，太脏了。
The door won't open. Could you give me a hand?
这门打不开，你能帮个忙吗？
These apples keep well through the winter.
这些苹果能放过整个冬天。
Her account deserves checking twice.
她的说法值得多核两遍。
易错提示
- 看到「物 + 副词 + 好/顺」就想到主动表被动：The pen writes smoothly，The door won't lock.
- need doing 与 need to be done 同义，want / require 也一样：The car wants repairing. = The car needs to be repaired.
- "好洗 / 写得顺 / 卖得快"中文本身就带被动味，英文这一格必须用主动形式，中间那个副词就是它的标志 —— 把 washes well 换成 was washed，句子就改口成"某一次真被洗了"，说的不是同一件事。
- need doing 里的 doing 表被动意思，但不能再叠一层进行：My hair needs cutting 就够，英文里没有 needs being cut 这种叠法 —— 一格里只留一层"在进行"。