不(bù) vs 没(méi)

不 vs 没

There are two ways to say ‘no’ in Chinese: 没 (méi) and 不 (bù).

1. 没 (méi) can never be used with 是 (shì).

e.g.
✘ 今天没是一月一号。
√ 今天不是一月一号。(Jīntiān búshì yī yuè yī hào.) Today is not January 1

✘ 我妹妹没是十岁。
√ 我妹妹不是十岁。(Wǒ mèimei i búshì shí suì.) My younger sister is not 10 years old.

2. 不 (bù) is used for the present and future time on a regular or habitual basis. Often, the adverbs of time, including words like today, tomorrow, next week, usually, or regularly, indicate which of these is meant.

e.g.
他现在不在。 (Tā xiànzài búzài.) He’s not home now.我从来不喝酒。 (Wǒ cónglái bù hējiǔ.) I never drink alcohol. –> as a habit, in general.

3. 不 (bù) is used to negate something subjective, such as “不想”，“不愿意” or “不要,” while 没 (méi) is used to negate something objective.

e.g.
A：你吃午饭了吗？(Nǐ chī wǔfànle ma?) Have you had lunch yet?
B：今天我不想吃饭。(Jīntiān wǒ bùxiǎng chīfàn.) I don’t want to eat today.

A：你吃午饭了吗？(Nǐ chī wǔfànle ma?) Have you had lunch yet?
B：我太忙了，没吃午饭。(Wǒ tài mángle, méi chī wǔfàn.) I was too busy to have lunch.

4. There are some collocations are often used to indicate someone’s capability, will, or judgment, such as “不知道” “不应该” “不清楚” “不会” etc.

e.g.
我不知道这件事。(Wǒ bù zhīdào zhè jiàn shì.) I don’t know about i

她不应该生气。(Tā bù yìng gāi shēngqì.) She should not be angry.

没

1. While 没 (méi) is used when talking about the past. Adverbs of time, including words like yesterday, last month, last year, before, or once long ago, indicate that something did not happen in the past. The past here includes the perfect tenses, those forms that used “have + the past participle,” as in ‘I have never been to XX’ 我没去XX。 (Wǒ méi qù. I didn’t go; I haven’t gone.)

e.g.
昨天我没上课。(Zuótiān wǒ méi shàngkè.) I didn’t go to class yesterday.

2. Only “没” is used to negate the continuation of an action or a state.

e.g.
门没关，进来吧！(Mén méi guān, jìnlái ba!) The door is open, come in!

A：你在看书吗？(Nǐ zài kànshū ma?) Are you reading a book?
B：我没在看书，在听音乐。(Wǒ méi zài kànshū, zài tīng yīnyuè.) I’m not reading a book. I’m listening to music.

3. Since single 有 (yŏu) means “have.” So 没有 (méiyŏu) means” not have.” “不” can’t be used to replace “没” in this case.

e.g.
我没有钱。(Wǒ méiyǒu qián. I don’t have money.)
他没有时间。(Tā méiyǒu shíjiān. He doesn’t have time.)

In spoken Mandarin, 没 is the short form of 没有, so 有 (yŏu) is often omitted.

e.g.
我没（有）去过长城。(Wǒ méi yŏu qùguò chángchéng.) I haven’t been to the Great Wall.
我没（有）汽车。(Wǒ méi yŏu qìchē.) I don’t have a car.