2 · Modal verbs
Néng and kěyǐ: able to and allowed to
ability, possibility and permission
Néng is being able in the circumstances, kěyǐ is being allowed — and when you ask permission, both will do.
能 is “can” in the sense of being able, here and now, given the circumstances or the state you are in: 我今天不能来, “I can’t come today” — something is stopping me. It also measures capacity: 他能游两公里, “he can swim two kilometres”. That he can swim at all is 会; how far he manages is 能.
可以 is permission, “may, be allowed to”: 这儿可以拍照吗, “can I take photos here?”. It also makes a suggestion: 你可以坐地铁, “you could take the underground”. When you ask for permission, both words work: 我能进来吗 and 我可以进来吗.
The negatives behave differently. 不能 is “cannot” or “must not”, and it is the everyday way to forbid something: 这儿不能停车, “you can’t park here”. 不可以 exists but sounds strict, like a teacher or a sign. The usual “no” to a request is 不行.
So English “can” becomes three questions. Did you learn it? Then 会. Is anything stopping you? Then 能. Does somebody have to let you? Then 可以. A sore leg does not make you forget how to run, so “I can’t run today” is 不能, not 不会.
The form
| able (circumstances) | 我明天能来。 |
| can’t (prevented) | 我明天不能来。 |
| allowed | 这儿可以拍照。 |
| asking permission | 我可以用一下你的笔吗？ |
| must not | 这儿不能抽烟。 |
| yes and no to a request | 可以。——不行。 |
The rules one by one
The form this topic is about
能: able to, because nothing stands in the way or because you have the capacity.
我感冒了，今天不能去上课。I’ve got a cold, so I can’t go to class today.
可以: allowed to; it also makes a suggestion.
你可以坐地铁去，很方便。You could take the underground; it is very convenient.
To ask for permission, 能 and 可以 are both fine.
我能坐这儿吗？Can I sit here?
To forbid, 不能 is the everyday word; 不可以 sounds stricter.
上课的时候不能玩手机。You may not play on your phone in class.
How much you manage takes 能, even when the skill itself is 会.
他一分钟能打一百个字。He can type a hundred characters a minute.
A closer look
Three cans side by side
One situation shows all three. 我会开车: I learned to drive. 我今天喝了酒，不能开车: I have had a drink today and cannot drive. 我十七岁，还不可以开车: I am seventeen and not yet allowed to drive.
The edges are softer than this suggests. 能 often appears where a rule is meant — 这儿不能停车 — because a rule is one of the circumstances that stop you. What does not soften is 会: when the point is a skill, it is the natural word.
Exceptions and special cases (1)
-
you answer a request for permission
say 可以 for yes and usually 不行 for no.
我可以走了吗？——不行，你还没做完。Can I go now? — No, you haven’t finished yet.
A bare 不可以 sounds like a teacher or a sign; 不行, “that won’t do”, is the everyday refusal.
How to spot it
- 能
- 可以
- 不能
- 可以…吗
- 不行
Example sentences
我可以试试这件衣服吗？May I try this on?
明天你能早点儿来吗？Can you come a bit earlier tomorrow?
这儿不能停车。You can’t park here.
我的腿受伤了，不能跑步。I’ve hurt my leg and can’t run.
你可以用我的电脑。You can use my computer.
这个房间能住四个人。This room sleeps four.
7 more example sentences
请问，这儿可以刷卡吗？Excuse me, can I pay by card here?
你明天能帮我一下吗？Could you give me a hand tomorrow?
医院里不能大声说话。You mustn’t talk loudly in the hospital.
他很能吃。He has a big appetite.
学生可以免费参观。Students can visit free of charge.
你可以先走，我一会儿就来。You can go ahead; I’ll be along in a minute.
我明天有事，不能参加会议。I have something on tomorrow and can’t attend the meeting.
Worth knowing (1)
-
Kěyǐ as “not bad”
As the predicate of a sentence, 可以 means “all right, not bad”: 这家饭馆还可以, “this restaurant is all right”. It is lukewarm praise, not enthusiasm.
我觉得这部电影还可以。I thought the film was all right.
The trap English speakers fall into
Watch out
You have not forgotten how to run; something is stopping you. 不会 says that you never learned how — or predicts that you won’t — so a sore leg needs 不能.
Learned it: huì. Nothing stopping you: néng. Somebody lets you: kěyǐ.
Your turn
8 exercises on this topic. Your answers are checked in the browser; none of them leaves your device.