Comparing "bu" and "mei"

Both 不 (bù) and 没 (méi) can be placed in front of a verb or adjective to negate its meaning. However, 不 (bù) and 没 (méi) are not usually interchangeable, so it's important to learn when you must use 不 (bù) as opposed to 没 (méi), and vice versa.

不 (bù) is for negating in the present and future

不 (bù) is generally used to negate an action that you do not want to do or do not intend to do (in the future). So expressing things like "I don't want to go" or "I'm not going" would be uses of 不 (bù).

Structure

Subj. + 不 + Verb

Examples

Whether it's "don't wanna do it" or "not gonna do it," use 不 (bù):

• 我 今天 晚上 不 喝酒。Wǒ jīntiān wǎnshang bù hējiǔ. Tonight I'm not going to drink.
• 爸爸 不 回来 吃 晚饭。Bàba bù huílái chī wǎnfàn. Dad is not coming back to eat dinner.
• 老板 明天 不 来 。Lǎobǎn míngtiān bù lái. The boss won't come tomorrow.
• 我 知道 这 个 周末 不 下雨。Wǒ zhīdào zhè ge zhōumò bù xiàyǔ. I know it's not going to rain this weekend.
• 你 女朋友 不 跟 你 一起 去 吗？Nǐ nǚpéngyou bù gēn nǐ yīqǐ qù ma? Is your girlfriend not going together with you?

不 (bù) is used to negate habitual actions

不 (bù) can be used to negate habitual actions, to express what you just aren't in the habit of doing, such as eating meat, or watching TV, or drinking alcohol. This is simply done by placing 不 (bù) in front of the verb.

Structure

Subj. + 不 + Verb + Obj.

Examples

• 我 不 吃 肉。Wǒ bù chī ròu. I don't eat meat.
• 你们 都 不 喝酒 吗？Nǐmen dōu bù hējiǔ ma? Do you all not drink alcohol?
• 他 不 喜欢 说话。Tā bù xǐhuan shuōhuà. He doesn't like to speak.
• 你 不 用 手机 看书 吗？Nǐ bù yòng shǒujī kàn shū ma? Do you not use your phone to read books?
• 你 晚上 不 洗澡 吗？Nǐ wǎnshang bù xǐzǎo ma? Don't you shower at night?

Please note that, while it is grammatically correct to use 没 (méi) in all the sentences above, 没 (méi) does not negate any habitual actions. The sentences above, if they contained 没 (méi) instead of 不 (bù), would express that the speaker didn't do the named activity (at one particular point in the past). So it would not be about habitual actions.

不 (bù) is normally used with Adjectives

When it comes to a simple negation of an adjective (such as "not cold"), use 不 (bù).

Structure

不 + Adj.

Examples

• 我们 不 饿。Wǒmen bù è. We're not hungry.
• 你 不 胖。Nǐ bù pàng. You are not fat.
• 我 家 不 远。Wǒ jiā bù yuǎn. My home is not far.
• 今天 不 冷。Jīntiān bù lěng. Today it isn't cold.
• 我 觉得 Starbucks 的 咖啡 不 好喝。Wǒ juéde Starbucks de kāfēi bù hǎohē. I think the coffee at Starbucks isn't good.

不 (bù) is used to ask questions

There are couple ways to use 不 (bù) to ask questions. One such way is through affirmative-negative questions. This is done by stating a verb and then immediately repeating that verb in a negative state (with 不 (bù)).

Structure

Subj. + Verb + 不 + Verb + Obj.

Examples

• 你 是 不是 我 的 老师？Nǐshì bù shì wǒ de lǎoshī? Are you my teacher or not?
• 她 想 不 想 来？Tāxiǎng bù xiǎnglái? Does she want to come?
• 你 爱 不 爱 我？Nǐài bù ài wǒ? Do you love me or not?
• 你们 周末 上 不 上班？Nǐmen zhōumòshàng bùshàng bān? Do you all go to work on weekends?
• 你 的 外国 朋友们 喜 不 喜欢 吃 中国菜？Nǐ de wàiguó péngyoumen xǐ bù xǐhuan chī Zhōngguó cài? Do your foreign friends like to eat Chinese food?

不 (bù) can also be used to form tag questions. Tag questions use the positive-negative question form, but are placed at the end of the sentence. Tag questions are used to seek approval or acceptance for a statement, very similar to the English "OK?" or "right?" You can't use 没 (méi) for this.

• 我们 去 吃饭 ，好 不 好？ Wǒmen qù chīfàn,hǎo bù hǎo? Let's go eat, is that OK?
• 你们 是 好 朋友 ，对 不 对？Nǐmen shì hǎo péngyou, duì bù duì? You are good friends, right?
• 我们 喝 咖啡 ，好 没 好？Wǒmen hē kāfēi,hǎo méi hǎo?Let's drink coffee, OK?
• 你 应该 去 上 课 ，对 没 对？Nǐ yīnggāi qù shàngkè,duì méi duì? You have to go to class, right?

没 (méi) is used to negate past actions

没 (méi) and 没有 (méiyǒu) can both be used to negate actions that occurred in the past, or to say that something has not happened yet.

Structure

Subj. + 没(有) + Verb + Obj.

Examples

• 他 没有 打 电话 给 我 。Tā méiyǒu dǎ diànhuà gěi wǒ. He did not give me a call.
• 你 没 去 上班 吗 ？Nǐ méi qù shàngbān ma? You didn't go to work?
• 我 昨天 没 喝 酒。Wǒ zuótiān méi hē jiǔ. I did not drink alcohol yesterday.
• 妈妈 没有 做 晚饭。Māma méiyǒu zuò wǎnfàn. Mom did not cook dinner.
• 他们 吃 完 饭 以后 没 付钱。 Tāmen chī wán fàn yǐhòu méi fùqián. They didn't pay after they finished eating.
• 我 昨天 不 喝酒。Wǒ zuótiān bù hē jiǔ.I not drink wine yesterday.
• 我 上个 周末 不 跟 他 见面。Wǒ shàng ge zhōumò bù gēn tā jiànmiàn. I didn't meet with him last weekend.
• 上个月 你 不 去 北京 吗？ Shàng ge yuè nǐ bù qù Běijīng? Did you not go to Beijing last month?

There are a few things worth noting in these examples. For one, it is still grammatically correct to leave out the 有 (yǒu) in the sentences using 没有 (méiyǒu). Also, the sentences using 不 (bù) would be grammatically correct, if not for the time words telling us that it is definitely the past we're talking about.

Only 没 is used to negate 有

没 (méi) can be used to negate the verb 有 (yǒu) ("to have") to mean "do not have." You can only use 没 (méi) to convey this meaning. It is grammatically incorrect to use 不 (bù) to negate 有 (yǒu).

Structure

Subj. + 没有 + Obj.

Examples

• 我 不 有 钱。Wǒ bù yǒu qián.
• 我 没有 钱。Wǒ méiyǒu qián. I don't have money.
• 他 不 有 女朋友。Tā bù yǒu nǚpéngyou.
• 他 没有 女朋友。Tā méiyǒu nǚpéngyou. He doesn't have a girlfriend.

There are times when you can leave out 有 (yǒu) entirely while still expressing 没有 (méiyǒu), (meaning "to not have" or "there is no"). One well-known example of this is 没办法 (méi bànfǎ) ("there is no way" [that's gonna happen]). Both 没 (méi) and 没有 (méiyǒu) are correct, however.

• 我 没 办法。Wǒ méi bànfǎ. I don't have a way.
• 我 没有 办法。Wǒ méiyǒu bànfǎ. I don't have a way.

(You can also use 没办法 (méi bànfǎ) to express other meanings.)

没 (méi) is used to make comparisons

没 (méi) or 没有 (méiyǒu) can be used to make simple comparisons meaning "not as... as...":

Structure

Noun 1 + 没有 + Noun 2 + Adj.

Examples

• 你 不 有 我 高。Nǐ bù yǒu wǒ gāo.
• 你 没有 我 高。Nǐ méiyǒu wǒ gāo.You are not as tall as me.
• 我 的 手机 不 有 他 的 手机 贵。 Wǒ de shǒujī bù yǒu tā de shǒujī guì.
• 我 的 手机 没有 他 的 手机 贵。Wǒ de shǒujī méiyǒu tā de shǒujī guì.My cell phone isn't as expensive as his.
• 我们 都 不 有 老板 忙。 Wǒmen dōu bù yǒu lǎobǎn máng.
• 我们 都 没有 老板 忙。 Wǒmen dōu méiyǒu lǎobǎn máng. We all are not as busy as the boss.
• 上海 的 冬天 不 有 北京 的 冬天 冷。 Shànghǎi de dōngtiān bù yǒu Běijīng de dōngtiān lěng.
• 上海 的 冬天 没有 北京 的 冬天 冷。 Shànghǎi de dōngtiān méiyǒu Běijīng de dōngtiān lěng. Shanghai winters are not as cold Beijing winters.

You can only use 没 (méi) or 没有 (méiyǒu) for this purpose, and not 不 (bù).

不 (bù) is used almost exclusively with some verbs

Certain verbs just don't get negated by 没 (méi) or 没有 (méiyǒu) ever. These include the verbs 是 (shì) ("to be") and 在 (zài) ("to be (in a place)"), as well as some psychological verbs such as 知道 (zhīdao) ("to know") and 认识 (rènshi) ("to know (a person)"). For these verbs, it's best to just take them on a case-by-case basis. Being aware of their existence can save you a fair bit of confusion.

• 他 以前 没 是 我的 老板。Tā yǐqián méi shì wǒ de lǎobǎn.
• 他 以前 不 是 我的 老板。Tā yǐqián bù shì wǒ de lǎobǎn. He was not my boss before.
• 我 没 知道 他 要 来 。 Wǒ méi zhīdao tā yào lái.
• 我 不 知道 他 要 来。Wǒ bù zhīdao tā yào lái. I didn't know he was coming.
• 他 小 时候 没 认识 她 。Tā xiǎo shíhou méi rènshi tā.
• 他 小时候 不 认识 她。Tā xiǎo shíhou bù rènshi tā.He did not know her when he was young.
• 昨天 我 没 在 家。Use of 没 with 在 is technically incorrect, but you sometimes hear it.Zuótiān wǒ méi zài jiā.
• 昨天 我 不 在 家 。Zuótiān wǒ bù zài jiā. I was not home yesterday.

Note that in non-standard Mandarin you might encounter exceptions to this rule. It's still useful to know the rule!

Sources and further reading

Websites

• http://www.docin.com/p-20925643.html
• http://wenku.baidu.com/view/e2e8eb2ce2bd960590c67703.html
• ChinesePod Qing Wen: When To Use “不” bù and “没” méi?

Videos

• Yoyo Chinese: Negation word 不
• Yoyo Chinese: Negation word 没

Books

• Chinese: An Essential Grammar, Second Edition (pp. 141-4) →buy
• Integrated Chinese: Level 1, Part 1 (3rd ed) (pp. 137-9) →buy
• New Practical Chinese Reader 1 (新实用汉语课本1) (p. 87) →buy
• New Practical Chinese Reader 1 (新实用汉语课本1)(2nd ed) (pp. 102, 250-1) →buy
• Chinese: An Essential Grammar, Second Edition (pp. 54-5) →buy
• New Practical Chinese Reader 3 (新实用汉语课本3) (pp. 33-4) →buy
• Chinese: An Essential Grammar, Second Edition (p. 51) →buy
• 现代汉语八百词（增订本） (p. 382) →buy
• Practicing HSK Grammar (语法精讲精炼) (p. 32) →buy
• 现代汉语八百词（增订本） (p. 383) →buy
• Integrated Chinese: Level 1, Part 1 (3rd ed) (p. 31) →buy
• Integrated Chinese: Level 1, Part 2 (1st ed) (pp. 85-86)　→buy
• New Practical Chinese Reader 1 (新实用汉语课本1)(2nd ed) (p. 218) →buy
• Reference:Chinese Grammar - Broken down into 100 items - Basic and Intermediate Levels (汉语语法百项讲练 - 初中级)(不 没p.156)→buy
• 40 Lessons for Basic Chinese Course (基础汉语40课上册） (p. 157-8)→buy