1. Meaning and Usage
不 (bù) is a fundamental negative adverb in Chinese, meaning "not" or "no". Its core usage is to negate verbs, adjectives, or entire clauses, expressing a general denial, a habit, a preference, or a statement of fact that is not true. It is used to negate actions in the present or future, and to negate descriptive qualities (adjectives).
2. Formulas and Examples
Case 1: Negating a Verb
Used to express that an action is not happening, will not happen, or is not a habit/preference.
$$不 + Verb$$
我不吃肉。 Wǒ bù chī ròu. I don't eat meat.
他不去学校。 Tā bú qù xuéxiào. He doesn't go to school.
Case 2: Negating an Adjective
Used to express that something does not possess a certain quality or characteristic.
$$不 + Adjective$$
这件衣服不贵。 Zhè jiàn yīfu bú guì. This piece of clothing is not expensive.
今天天气不好。 Jīntiān tiānqì bù hǎo. The weather is not good today.
Case 3: Negating "是 (shì)" (to be)
When "是" acts as a verb linking a subject to a noun predicate, "不" negates it.
$$不 + 是 + Noun$$
我不是老师。 Wǒ bú shì lǎoshī. I am not a teacher.
这不是我的书。 Zhè bú shì wǒ de shū. This is not my book.
Case 4: Negating a Volitional Verb or Opinion
Used to express a lack of desire, intention, or a disagreement.
$$不 + Volitional Verb / Opinion$$
我不想去。 Wǒ bù xiǎng qù. I don't want to go.
我认为不对。 Wǒ rènwéi bú duì. I think it's not right.
3. Essential HSK Tips & Common Mistakes
HSK Tip 1: Differentiating 不 (bù) and 没 (méi)
This is one of the most crucial distinctions for English speakers.
- 不 (bù) negates general statements, habits, preferences, future actions, and adjectives. It expresses a refusal or a contrary opinion.
- 没 (méi) primarily negates past actions (often in conjunction with
有or simplyVerbwithout了/过to indicate past completed action) and the existence of something (negating有).
我不吃饭。 (Habit: I don't eat rice usually.) Wǒ bù chī fàn. I don't eat rice.
我没吃饭。 (Past action: I didn't eat rice yet/at that time.) Wǒ méi chī fàn. I didn't eat rice.
HSK Tip 2: Tonal Change of 不 (bù)
When 不 (bù) is followed by a character with a fourth tone, 不 changes its tone from fourth tone (bù) to second tone (bú). In all other cases (followed by first, second, third, or neutral tone), it remains its original fourth tone (bù).
他不去。 (bú qù - 去 is 4th tone) Tā bú qù. He doesn't go.
我不好。 (bù hǎo - 好 is 3rd tone) Wǒ bù hǎo. I am not good.
HSK Tip 3: Always Use 没 (méi) to Negate 有 (yǒu)
You never use 不 (bù) to negate the verb 有 (yǒu, to have/exist). Always use 没 (méi).
我没有钱。 (Correct) Wǒ méi yǒu qián. I don't have money.
我没有时间。 (Correct) Wǒ méi yǒu shíjiān. I don't have time.
Common Mistake: Using 不 for Past Actions
A common mistake is to use 不 to negate an action that happened in the past. Remember to use 没 (méi) for past actions.
我没看那个电影。 (Correct: Negating a past action) Wǒ méi kàn nà ge diànyǐng. I didn't watch that movie.
我没学中文。 (Correct: Negating a past action) Wǒ méi xué Zhōngwén. I didn't learn Chinese.