3 · Complements after the verb
Can or cannot: potential complements
de or bu between the verb and its result
De or bu between a verb and its complement says whether the result is possible: kàndedǒng, kànbudǒng.
Almost any result or direction complement can be turned into a statement about possibility by putting 得 (“can”) or 不 (“cannot”) between the verb and the complement: 看懂 → 看得懂, “can understand (when reading)”, 看不懂, “cannot understand”; 回来 → 回得来, 回不来. Both small words are unstressed, and this site writes the whole form as one word.
The form says whether circumstances or ability allow the result, however hard you try. The negative is far more common than the positive: 听不懂, 买不到, 找不到, 吃不完, 睡不着. The positive mostly appears in questions and in the answers to them: 你看得懂吗？——看得懂。
English uses “can” or “can’t” for all of this, and the temptation is to translate with 能. But 不能 usually means “not allowed” or a general inability, while the potential complement says that the intended result will not come about: 不能进去 is “you may not go in”; 进不去 is “you can’t get in” — the door is locked, the room is full.
Some potential forms have become fixed words with meanings of their own: 来不及 “there is not enough time”, 来得及 “there is still time”, 买不起 “cannot afford”, 对不起 “sorry”. Two complements exist almost only in this form: 了, as in 吃不了 “cannot manage (to eat it all)”, and 动, as in 拿不动 “too heavy to carry”.
The form
| can understand (reading) | 这本书我看得懂。 |
| cannot understand (listening) | 他说得太快，我听不懂。 |
| cannot get hold of | 票买不到了。 |
| a question with both forms | 你看得见看不见？ |
| a direction complement | 我今天晚上回不来。 |
| no time | 快走吧，要来不及了！ |
The rules one by one
The form this topic is about
得 between the verb and the complement says the result can be reached; 不 says it cannot.
黑板上的字你看得清吗？Can you read the writing on the blackboard clearly?
Use the potential form when circumstances or ability stop the result, not when something is forbidden.
菜太多了，我们两个人吃不完。There is too much food — the two of us cannot finish it.
The negative is far more common; the positive mostly asks or answers a question.
你听得懂上海话吗？Can you understand the Shanghai dialect?
An object comes after the potential form or at the front of the sentence.
我找不到我的眼镜了。I can't find my glasses.
Some potential forms are fixed words with a meaning of their own.
这么贵的车我买不起。I can't afford such an expensive car.
A closer look
Bù néng or the potential form?
A sign on a door saying 不能进去 forbids entry. A person in front of a locked door says 进不去: nobody forbids it, it just cannot be done. In the same way 我不能吃辣的 often means “I mustn’t eat spicy food” (doctor’s orders), while 我吃不了辣的 means “I can’t take spicy food”.
The two can be combined when the speaker wants to stress possibility: 你能看得懂吗？ is common in speech. What does not work is 不能 before a plain result complement when you mean that the result will not come: “I can’t understand” is 听不懂, not 不能听懂.
Exceptions and special cases (1)
-
the result is something you are not allowed or not supposed to do
use 不能, not the potential form.
这儿不能抽烟。You cannot smoke here.
The potential form describes what circumstances allow, not what rules allow.
How to spot it
- …得…
- …不…
- 来不及
- 买不起
- 听不懂
Example sentences
他的字太小了，我看不清楚。His handwriting is too small — I can't read it clearly.
现在去机场还来得及吗？Is there still time to get to the airport?
门太窄了，沙发搬不进去。The door is too narrow — the sofa won't go in.
昨天晚上太热了，我一直睡不着。It was so hot last night that I couldn't get to sleep.
这个箱子太重了，我拿不动。This suitcase is too heavy — I can't lift it.
你说的那本书在书店里买得到吗？Can you get the book you mentioned in a bookshop?
8 more example sentences
这个问题太难了，我回答不了。This question is too hard — I can't answer it.
太远了，我看不见。It's too far away — I can't see it.
今天的作业你做得完吗？Can you get today's homework done?
我走了一天，现在实在走不动了。I've been walking all day and now I really can't go any further.
你放心，我记得住。Don't worry — I can remember it.
雨这么大，他今天回不来了。With this much rain, he won't be able to get back today.
这种水果在我们那儿买不到。You can't get this kind of fruit where I come from.
房间里太吵了，我听不清你说什么。It's too noisy in here — I can't hear what you're saying.
Worth knowing (1)
-
Duìbuqǐ, kànbuqǐ, liǎobuqǐ
Several everyday words are potential forms that have frozen into vocabulary: 对不起, literally “cannot face (you)”, is “sorry”; 看不起, “cannot look up to”, is “look down on”; and 了不起 is “amazing”.
她十岁就会说三种语言，真了不起！She could speak three languages at ten — amazing!
The trap English speakers fall into
Watch out
English “I can’t understand” leads straight to 不能. But nobody is forbidding you to understand; the result simply does not come about. That is the job of the potential form, which puts 不 between the verb and its result.
Verb, de or bu, result: kàndedǒng, you can; kànbudǒng, you cannot, however hard you try.
Your turn
9 exercises on this topic. Your answers are checked in the browser; none of them leaves your device.