Comparing "hui," "neng," "keyi"

This is one of the trickiest comparisons, as 会 (huì), 能 (néng), and 可以 (kěyǐ) are often translated as "can." Sometimes they are explained as: 会 means "know how to," 能 means "to be able to," and 可以 means "to have permission to." Actually, they overlap somewhat.

Basic Meanings

The words 会 (huì), 能 (néng), and 可以 (kěyǐ) actually overlap a little in meaning. The first step is to understand their basic meanings, though:

1. 会 (huì) can mean "know how to" and can express an action that you had to learn or be trained in to do.
2. 能 (néng) means "to be able to" and expresses having a certain ability or having obtained a certain minimum requirement.
3. 可以 (kěyǐ) means "may" or "to be allowed to" and expresses having another person's permission.

As for overlap, this graphic helps explain nicely:

The regions marked by letters are explained in the sections below:

• A: ability in the sense of “know how to” (会 (huì) is more common than 能 (néng))
• B: permission/request (use 能 (néng) or 可以 (kěyǐ))
• C: possibility (use 能 (néng) or 可以 (kěyǐ))
• D: permission not granted (use 不可以 (bù kěyǐ))
• E: impossibility (use 不能 (bù néng))

Expressing Ability

Both 会 and 能 can be used to express ability in something.

Structure

会／能 + Verb

Examples

• 我们 都 会 游泳 。Wǒmen dōu huì yóuyǒng.We all can swim.
• 他 不 会 修 电脑 。Tā bù huì xiū diànnǎo.He doesn't know how to fix computers.
• 你 真的 能 吃 三 碗 米饭 吗 ？Nǐ zhēnde néng chī sān wǎn mǐfàn ma?Are you really able to eat three bowls of rice?

• A: 你 会 说 中文 吗 ？Nǐ huì shuō Zhōngwén ma?Can you speak Chinese?
• B: 不 好意思 ，我 只 能 说 一点 。Bù hǎoyìsi, wǒ zhǐ néng shuō yīdiǎn.Sorry, I can only speak a little.

Expressing Permission

可以 is used to ask for or give permission. However, 能 can also be used to replace 可以 interchangeably.

Note: When a question is asked using 能 or 可以 it can be answered with 不能 or 不可以, meaning no, and only 可以 meaning yes. Chinese don't really answer with just 能。

Structure

可以 / 能 + Verb

Examples

• 我 可以 走 了 吗 ？Wǒ kěyǐ zǒu le ma?Am I allowed to leave now?
• 你 能 不 能 帮 我 一下 吗 ？Nǐ néng bu néng bāng wǒ yīxià ma?Could you help me a bit?
• 动物 不 能 进 。Dòngwù bù néng jìn.Animals are not allowed to come in.

• A: 我 能 在 这里 抽烟 吗 ？Wǒ néng zài zhèlǐ chōuyān ma?Can I smoke here?
• B: 不 可以 。Bù kěyǐ.No, you can't.

Expressing Possibility

能 and 可以 can also be used to express possibility.

Structure

可以 / 能 + Verb

Example

• 明天 你 能 早点 来 吗 ？Míngtiān nǐ néng zǎodiǎn lái ma?Is it possible for you to come al little earlier tomorrow?
• 可 不 可以 换 一 个 ？Kě bu kěyǐ huàn yī gè?Is it possible to change it?
• 能 不 参加 吗 ？Néng bù cānjiā ma?Is it possible to not attend?

• A:能 不 能 取消 今天 的 课 ？Néng bu néng qǔxiāo jīntiān de kè?Is it possible to cancel today's lesson?
• B: 不 能 。Bù néng.Impossible.

Talking about the Future

Only 会 can be used to mean something is going to happen. It expresses that something in the future will happen and is often used to express trends or possibilities.

Structure

会 + Verb / Adj.

Examples

• 他 不 会 跟 你 结婚 。Tā bù huì gēn nǐ jiéhūn.He's not going to marry you.
• 你 会 生 我 的 气 吗 ？Nǐ huì shēng wǒ de qì ma?Will you be mad at me?
• 这样 穿 会 好看 吗 ？Zhèyàng chuān huì hǎokàn ma?Will I look good if I dress like this?

• A: 今天 会 下雨 吗 ？Jīntiān huì xiàyǔ ma?Is it going to rain today?
• B: 我看 不 会 。Wǒ kàn bù huì.I don't think it will.

Using Adverbs to Add Emphasis

By placing 很 (hěn) before 会, it adds emphasis to the level of ability and skill on the action presented. 很会 is commonly used to mean 'to be good at" and expresses being very skillful at something, or doing something very well. It can be translated as "really can," as in "you really can speak Chinese!," in other words, "you are good at speaking Chinese."

When 很 is placed in front of 能, the meaning takes on a amazed/surprised tone on the action. Although more rarely used, it emphasis quantity and amount. 很能 is most commonly used with 吃(chī) to eat, and 睡 (shuì) to sleep. It's like the English equivalent of saying you "can really" do something. For example saying that someone "can really sleep" means that they can sleep a lot.

Note: 很可以 is not a phrase and therefore can not be used with 会 to add emphasis. Other adverbs like 真 (zhēn), 太 (tài), 这么 (zhème) etc. can also be used.

Structure

很 + 会／能 + Verb

Examples

• 这个 女生 很 会 打扮 。Zhège nǚshēng hěn huì dǎban.This girl knows how to dress up really well.
• 我 妈妈 很 会 做饭 。My mom cooks very well.Wǒ māma hěn huì zuòfàn.My mother really knows how to cook.
• 他 很 会 说话 。The subject has good speaking skills.Tā hěn huì shuōhuà.He's a smooth talker.
• 他 很能 说 。Tā hěn néng shuō.He's quite a talker.

Note that 很可以说 is wrong and it doesn't mean anything.

Examples used with other adverbs:

• 他 太 能 睡 了 。The subject can sleep a lot, for many hours.Tā tài néng shuì le.He can really sleep.
• 没想到 你 这么能 吃苦 。Méixiǎngdào nǐ zhème néng chīkǔ.I didn't expect you to be a person who can handle so many burdens.
• 你 真能 吃 !The subject can eat a lot.Nǐ zhēn néng chī!Wow, you really can eat!
• 中国 人 真会 吃 !The subject has great knowledge about food and its culture, a true connoisseur.Zhōngguó rén zhēn huì chī!Chinese people really can eat.

Note that 很可以吃 is wrong and it doesn't mean anything.

Similar expression with different meanings

• 我 的 脚 好 了 ，现在 又 能 跳舞 了 。Wǒ de jiǎo hǎo le, xiànzài yòu néng tiàowǔ le.I am able to dance now since my foot is better. (The condition changed)
• 我 学 了 两 个 月 ，现在 我 会 跳舞 了 。Wǒ xué le liǎng gè yuè, xiànzài wǒ huì tiàowǔ le.I studied for two months. I know how to dance now. (It's a learned skill)
• 我 爸妈 同意 了 ，现在 我 可以 跳舞 了 。Wǒ fùmǔ tóngyì le, xiànzài wǒ kěyǐ tiàowǔ le.My parents agreed. I'm allowed to dance now. (The dad gave permission)

Note that none of the three can be followed by the aspectual particle 过.

For a good visualization on how these three overlap, check out the Chinese Modal Verb Venn Diagram.

See Also

• Auxiliary verb "hui" for "will"
• Expressing a learned skill
• Expressing ability or possibility
• Expressing permission

Sources and further reading

Books

• 对外汉语教学语法释疑201例 (pp. 55, 65) [ →buy]
• Integrated Chinese: Level 1, Part 1 (3rd ed) (pp. 219-20) Anything Goes (无所不谈) →buy

Dictionaries

• 现代汉语词典（第5版） (pp. 989, 773, 610) 卓越汉语－公司实战篇 →buy

Websites

• Sinosplice: Chinese Modal Verb Venn Diagram