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.
- 1 不 (bù) Negates in the Present and Future
- 2 不 (bù) Negates Habitual Actions
- 3 不 (bù) Is Normally Used with Adjectives
- 4 不 (bù) Is for Asking Questions
- 5 没 (méi) Negates Past Actions
- 6 Only 没 (méi) Negates 有 (yǒu)
- 7 没 (méi) Is for Making Comparisons
- 8 不 (bù) Is Used Almost Exclusively with Certain Verbs
- 9 Sources and further reading
不 (bù) Negates 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).
Subj. + 不 + Verb
Whether it's "don't wanna do it" or "not gonna do it," use 不 (bù):
- 我 今天 晚上 不 喝酒。Tonight I'm not going to drink.
- 爸爸 不 回来 吃 晚饭。Dad is not coming back to eat dinner.
- 老板 明天 不 来 。The boss won't come tomorrow.
- 我 知道 这 个 周末 不 下雨。I know it's not going to rain this weekend.
- 你 女朋友 不 跟 你 一起 去 吗？Is your girlfriend not going with you?
不 (bù) Negates 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.
Subj. + 不 + Verb + Obj.
- 我 不 吃 肉。I don't eat meat.
- 你们 都 不 喝酒 吗？Do you all not drink alcohol?
- 他 不 喜欢 说话。He doesn't like to speak.
- 你 不 用 手机 看书 吗？Do you not use your phone to read books?
- 你 晚上 不 洗澡 吗？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).
不 + Adj.
- 我们 不 饿。We're not hungry.
- 你 不 胖。You are not fat.
- 我 家 不 远。My home is not far.
- 今天 不 冷。Today it isn't cold.
- 我 觉得 Starbucks 的 咖啡 不 好喝。I think the coffee at Starbucks isn't good.
不 (bù) Is for Asking 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)).
Subj. + Verb + 不 + Verb + Obj.
- 你 是 不是 我 的 老师？Are you my teacher or not?
- 她 想 不 想 来？Does she want to come?
- 你 爱 不 爱 我？Do you love me or not?
- 你们 周末 上 不 上班？Do you all go to work on weekends?
- 你 的 外国 朋友们 喜 不 喜欢 吃 中国菜？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 没 好？
- 我们 去 吃饭 ，好 不 好？Let's go eat, is that OK?
- 你们 是 好 朋友 ，对 没 对？
- 你们 是 好 朋友 ，对 不 对？You are good friends, right?
没 (méi) Negates 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.
Subj. + 没(有) + Verb + Obj.
- 他 没有 打 电话 给 我 。He did not give me a call.
- 你 没 去 上班 吗 ？You didn't go to work?
- 我 昨天 没 喝酒。I did not drink alcohol yesterday.
- 妈妈 没有 做 晚饭。Mom did not cook dinner.
- 他们 吃 完 饭 以后 没 付 钱。They didn't pay after they finished eating.
- 我 昨天 不 喝酒。I not drink wine yesterday.
- 我 上个 周末 不 跟 他 见面。I not meet with him last weekend.
- 上个月 你 不 去 北京 吗？ 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 (méi) Negates 有 (yǒu)
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).
Subj. + 没有 + Obj.
- 我 不 有 钱。
- 我 没有 钱。I don't have money.
- 他 不 有 女朋友。
- 他 没有 女朋友。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。I don't have a way.
- 我 没有 办法。I don't have a way.
(You can also use 没办法 (méi bànfǎ) to express other meanings.)
没 (méi) Is for Making Comparisons
没 (méi) or 没有 (méiyǒu) can be used to make simple comparisons meaning "not as... as...":
Noun 1 + 没有 + Noun 2 + Adj.
- 你 不 有 我 高。
- 你 没有 我 高。You are not as tall as me.
- 我 的 手机 不 有 他 的 手机 贵。
- 我 的 手机 没有 他 的 手机 贵。My cell phone isn't as expensive as his.
- 我们 都 不 有 老板 忙。
- 我们 都 没有 老板 忙。We all are not as busy as the boss.
- 上海 的 冬天 不 有 北京 的 冬天 冷。
- 上海 的 冬天 没有 北京 的 冬天 冷。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 Certain 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 (zhīdào) ("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。
- 他 以前 不 是 我的 老板。He was not my boss before.
- 我 没 知道 他 要 来 。
- 我 不 知道 他 要 来。I didn't know he was coming.
- 他 小 时候 没 认识 她 。
- 他 小时候 不 认识 她。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.
- 昨天 我 不 在 家 。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
- ChinesePod Qing Wen: When To Use “不” bù and “没” méi?
- Chinese: An Essential Grammar, Second Edition (pp. 141-4) Anything Goes (无所不谈) →buy
- Integrated Chinese: Level 1, Part 1 (3rd ed) (pp. 137-9) Anything Goes (无所不谈) →buy
- New Practical Chinese Reader 1 (新实用汉语课本1) (pp. 87) Anything Goes (无所不谈) →buy
- New Practical Chinese Reader 1 (新实用汉语课本1)(2nd ed) (pp. 102, 250-1) Anything Goes (无所不谈) →buy
- Chinese: An Essential Grammar, Second Edition (pp. 54-5) Anything Goes (无所不谈) →buy
- New Practical Chinese Reader 3 (新实用汉语课本3) (pp. 33-4) Anything Goes (无所不谈) →buy
- Chinese: An Essential Grammar, Second Edition (pp. 51) Anything Goes (无所不谈) →buy
- 现代汉语八百词（增订本） (pp. 382) [ →buy]
- Practicing HSK Grammar (语法精讲精炼) (pp. 32) Anything Goes (无所不谈) →buy
- 现代汉语八百词（增订本） (pp. 383) [ →buy]
- Integrated Chinese: Level 1, Part 1 (3rd ed) (pp. 31) Anything Goes (无所不谈) →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) (pp. 218) Anything Goes (无所不谈) →buy
- Reference:Chinese Grammar - Broken down into 100 items - Basic and Intermediate Levels (汉语语法百项讲练 - 初中级) (pp. 156) [ →buy]
- 40 Lessons for Basic Chinese Course (基础汉语40课上册） (pp. 157-8) [ →buy]