不 vs 没 (bù vs méi): when to use each negator
The key distinction between 不 (bù) and 没 (méi) is that 不 negates actions in present, future, habitual, or volitional contexts (and adjectives), while 没 negates completed actions, past experiences, and possession. When negating a completed action with 没, the aspect marker 了 is dropped (e.g., 我没去, not 我没去了). 没 also acts as a standalone negator for possession in colloquial speech (e.g., 我没钱).
不 and 没 are the two main negation particles in Mandarin, but they are not interchangeable. 不 is used for general negation that does not imply completion—present, future, habitual actions, desires, and stative verbs (including adjectives). It can also combine with 了 to indicate a change of state (e.g., 不吃了 'no longer eat'). 没 negates completed actions (corresponding to 了), past experiences (corresponding to 过), and existence/possession (as 没/没有). When negating a past action with 没, the aspect marker 了 must be removed. 没 also functions as a standalone verb for possession in informal contexts.
When to use each
Use 不 to negate verbs in present, future, habitual, and volitional contexts. It is also used to negate adjectives. 不 can appear with 了 to express 'no longer' (e.g., 我不去了 'I'm not going anymore'). It does not negate completed actions or past experiences.
When 不 appears before a verb with 了 at the end of the sentence (不...了), it signals a change of state, not the negation of a past completion. For example, 我不吃了 means 'I won't eat anymore' (change of intention), not 'I did not eat'.
Use 没 to negate that an action occurred (completed) or that someone has experienced something (with 过). For completed actions, the 了 marker is always dropped (e.g., 我没去, not 我没去了). 没 also negates possession, often as 没有, but 没 alone is acceptable colloquially (e.g., 我没钱 'I have no money'). 没 cannot negate future actions, habits, or adjectives.
With 过, the 过 is retained: 我没去过 'I haven't been there'. In rapid speech, 没 sometimes shortens 没有, but it remains a valid negator for existence or possession (e.g., 没问题的 'no problem' is common).
At a glance
| 不 | 没 | |
|---|---|---|
| Basic meaning | General negation (present, future, habitual, volitional; also adjectives) | Negation of completion, past experience, or existence/possession |
| Tense / aspect | Present, future, habitual, volitional; no inherent completion | Past, experiential, or present state of lacking |
| With 了 | 不 + verb + 了 → change of state ('no longer') | 没 + verb (了 is dropped) → negation of completion ('did not') |
| With 过 | Not used to negate experience (incorrect: 不+ verb + 过) | 没 + verb + 过 → negation of past experience ('have never') |
| Negating adjectives | Yes, e.g., 不好 (bù hǎo), 不漂亮 (bù piàoliang) | No (except fixed phrases like 没意思 'not interesting') |
| Negating possession (有) | Not used (不有 is incorrect) | 没 (or 没有) + noun, e.g., 我没(有)钱 |
Examples
- 不我不吃辣。Wǒ bù chī là.I don't eat spicy food (habitual).用 不 表示习惯性动作。
- 不明天我不去。Míngtiān wǒ bù qù.I'm not going tomorrow (future).用 不 否定将来计划。
- 不我不去了，太累了。Wǒ bù qù le, tài lèi le.I'm not going anymore (change of intention), too tired.不...了 表示状态改变。
- 没昨天我没去。Zuótiān wǒ méi qù.I didn't go yesterday.否定过去完成：去掉 了。
- 没我没吃过这个菜。Wǒ méi chī guo zhège cài.I haven't eaten this dish before.带 过 保留。
- 没我没钱，不能买。Wǒ méi qián, bù néng mǎi.I have no money, can't buy it.没 直接否定有无，口语常见。
Common mistakes
- Using 不 to negate a completed past action: e.g., ✗ 昨天我不去 should be 昨天我没去.
- Using 没 to negate a future or habitual action: e.g., ✗ 明天我没去 or ✗ 我常没去 should be 明天我不去, 我常不去.
- Keeping 了 after 没 when negating completion: e.g., ✗ 我没去了 should be 我没去 (the 了 is dropped).
- Assuming 没 always requires 有: While 没有 is common, 没 alone is correct in colloquial possession (e.g., 我没钱, 没笔).
- Using 不 with 过 to negate experience: e.g., ✗ 我不去过 should be 我没去过.
FAQ
- When do I use 不 vs 没?
- Use 不 for general negation in present, future, habitual, or volitional contexts, and with adjectives. Use 没 to negate that something happened (completion) or that you have done something (experience with 过). Also use 没 for 'not have' (possession).
- Can 不 be used for past actions?
- No, 不 is not used to negate a single completed action in the past. Use 没 instead. However, 不 can describe past habits or general truths (e.g., 以前我不吃辣 'I didn't eat spicy food before' — a habit, not a single event).
- Is 没 always followed by 有?
- No. In colloquial Chinese, 没 can stand alone as the negator for possession (e.g., 我没钱, 没时间). 没有 is more formal and can be used as a full verb. Both are correct; 没 alone is not wrong.
- What is the difference between 不...了 and 没... (for past)?
- 不...了 indicates a change of state or intention (e.g., 我不去了 'I am no longer going' — had planned to go but changed mind). 没 + verb negates the occurrence of a past action (e.g., 我没去 'I didn't go' — factual negation). They are not interchangeable.