Vietnamese verbs do not acquire a negative past or progressive ending. Instead, a negator and an aspect-time expression each contribute their own meaning. Không ăn denies eating, chưa ăn says eating has not happened up to the relevant time, đã không ăn locates a non-event in an established past situation, and không còn ăn nữa marks a changed habit. Choosing the negative therefore tells the listener more than English not does by itself.
The organizing principle is aspect plus speech act. Ask whether you are denying an event, presenting it as still pending, locating its absence in the past or future, or correcting someone else's assumption. This page focuses on that interaction. It does not cover two negatives in one clause; that belongs to Double Negation.
The basic decision aid
| Intended meaning | Usual pattern | Typical interpretation |
|---|---|---|
| neutral denial | không + predicate | does not / did not, with time from context |
| pending up to now/then | chưa + predicate | has not / had not ... yet |
| past non-occurrence | đã không + predicate | did not, against an established expectation or alternative |
| future non-occurrence | sẽ không + predicate | will not |
| absence of prior experience | chưa từng + predicate | has never ... before |
| changed state | không còn + predicate + nữa | no longer |
| emphatic contradiction | đâu có + predicate | didn't / don't, contrary to what you imply |
Aspect words are optional when time is recoverable. Hôm qua tôi không đi làm is complete because hôm qua supplies the past frame. Adding đã is not a mechanical translation of English did.
Hôm qua tôi không đi làm vì bị sốt.
Yesterday I didn't go to work because I had a fever.
Tôi chưa ăn; đợi tôi mười phút nhé.
I haven't eaten yet; wait for me for ten minutes, okay?
Không and chưa make different timelines
Không rejects the predicate as true in the relevant situation. Chưa places the expected endpoint beyond the reference time. That continuation is why chưa often corresponds to English not yet, haven't, or hadn't rather than simple not.
Tôi không ăn thịt.
I don't eat meat.
Tôi chưa ăn sáng.
I haven't eaten breakfast yet.
The second sentence normally keeps breakfast possible. The first describes a refusal, choice, or general fact, depending on context. A time phrase can move the reference point into the past:
Lúc xe đến, chúng tôi vẫn chưa ăn xong.
When the bus arrived, we still hadn't finished eating.
Here vẫn chưa means “still not yet,” and xong supplies a completion boundary. Vietnamese does not need a special pluperfect verb form: the arrival sets the past reference time, while chưa ... xong says the meal had not reached completion by then.
Negating đã, đang, sẽ, and từng
With an established past frame, đã không + V presents non-occurrence as a past fact. It often carries contrast: the person could or was expected to act but did not.
Dù đã được nhắc, anh ấy vẫn không gửi báo cáo đúng hạn.
Although he had been reminded, he still didn't submit the report on time.
Cuối cùng, chúng tôi đã không ký hợp đồng đó.
In the end, we did not sign that contract.
For current progress, a speaker commonly negates the predicate within a current frame: hiện giờ không làm, đang không hoạt động, or a lexical construction suited to the situation. Đang không + V is useful when the state of not doing is itself current and contrastive. It is less neutral than simply omitting đang.
Hệ thống đang không hoạt động, nên anh thử lại sau nhé.
The system is currently not working, so please try again later.
For a straightforward denial of an ongoing action, natural conversation often uses không + V + đâu with context rather than forcing không đang word for word from English.
Tôi không ngủ đâu; tôi đang nghe chị nói đây.
I'm not sleeping; I'm listening to you.
Future sẽ normally precedes không: sẽ không V. The future remains asserted, and what lies inside its scope is negative.
Từ tháng sau, cửa hàng sẽ không mở cửa vào Chủ nhật.
Starting next month, the shop will not open on Sundays.
Từng evokes at least one prior occasion. To deny previous experience, Vietnamese normally uses chưa từng, not a literal affirmative từng followed by a misplaced negative.
Tôi chưa từng gặp tình huống như thế này.
I have never encountered a situation like this before.
Rồi, còn, and a change of state
Clause-final rồi can signal that a new state now holds. Its negative counterpart is often not không ... rồi, but chưa ... when the change has not occurred, or không còn ... nữa when an earlier state has ended.
Máy đã được sửa xong rồi.
The machine has now been repaired.
Máy chưa được sửa xong.
The machine hasn't been fully repaired yet.
Quán đó không còn bán món này nữa.
That restaurant no longer serves this dish.
The paired còn ... nữa expresses continuation in positive clauses; under negation, không còn ... nữa closes off that continuation. In casual speech, either còn or nữa may sometimes be omitted when context is strong, but the full pair makes the change especially clear.
Speech act matters as much as time
The same event can be denied, postponed, prohibited, or contradicted:
| Form | Function | What the speaker does |
|---|---|---|
| không biết | neutral denial | says knowing is false |
| chưa ăn | not-yet | keeps eating pending |
| chẳng ai | negative quantification | says there is no relevant person |
| đừng đi | prohibitive | asks the listener not to go |
| không phải là | corrective/identificational | rejects a label or explanation |
| đâu có quên | contradiction | pushes back against an accusation |
Chẳng is more expressive than neutral không; chả is strongly conversational (informal; especially Northern). Hề strengthens a licensed negative, as in không hề quên “did not forget at all.” These do not simply mark tense. Đừng selects a directive speech act, so it cannot replace sẽ không in a prediction.
A dialogue where the negative changes the schedule
— Anh ăn trưa chưa? — Chưa ăn; cuộc họp vẫn chưa xong.
— Have you had lunch yet? — Not yet; the meeting still hasn't finished.
— Tôi tưởng anh đã quên buổi hẹn. — Tôi đâu có quên; tôi đã không ra ngoài được vì xe hỏng.
— I thought you had forgotten the appointment. — I didn't forget; I wasn't able to go out because my vehicle broke down.
— Vậy chiều nay anh đến chứ? — Có, nhưng tôi sẽ không đến trước ba giờ được.
— So you'll come this afternoon, right? — Yes, but I won't be able to arrive before three.
Chưa ăn keeps lunch pending. Vẫn chưa xong says the expected endpoint has not been reached. Đâu có quên corrects an accusation, while đã không ... được reports a past failure under an already established timeline. Finally, sẽ không places the negative limit in the future.
Common Mistakes
1. Using không where “not yet” is essential.
❌ Tôi không gửi hồ sơ.
Wrong for ‘I haven't submitted the application yet’; this normally says I do not submit it or will not submit it.
✅ Tôi chưa gửi hồ sơ; chiều nay tôi sẽ gửi.
I haven't submitted the application yet; I'll submit it this afternoon.
The repair works because chưa presents the event as unrealized but still possible.
2. Placing the negator after the lexical verb on an English model.
❌ Hôm qua tôi đi không làm.
Incorrect for ‘I didn't go to work yesterday’; không cannot be inserted after đi this way.
✅ Hôm qua tôi không đi làm.
Yesterday I didn't go to work.
Standard clausal negation precedes the predicate it negates.
3. Reversing future scope.
❌ Ngày mai tôi không sẽ ở nhà.
Incorrect — this is not the normal order for future negation.
✅ Ngày mai tôi sẽ không ở nhà.
I won't be home tomorrow.
Sẽ establishes the future frame; không then negates the predicate inside it.
4. Translating English past tense by adding đã everywhere.
❌ Hôm qua trời đã không mưa.
Needlessly marked in a neutral weather report; it sounds contrastive, as though rain had been expected.
✅ Hôm qua trời không mưa.
It didn't rain yesterday.
Use đã không when past contrast or an unrealized expectation matters, not merely because English uses didn't.
5. Treating a prohibition as future negation.
❌ Em sẽ không chạm vào ổ điện!
Wrong as a direct warning; this predicts that you won't touch the outlet.
✅ Đừng chạm vào ổ điện!
Don't touch the electrical outlet!
The correction changes the speech act from prediction to prohibition.
Key Takeaways
- Không denies; chưa means an expected endpoint has not been reached.
- Đã không is a marked past non-occurrence, while sẽ không is the normal future-negative order.
- Chưa từng denies prior experience; không còn ... nữa marks a discontinued state.
- Time expressions often make an aspect marker unnecessary.
- Vietnamese negative choice encodes the speaker's view of the timeline and the speech act, not a conjugated tense.
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Start learning Vietnamese →Related Topics
- Chưa and Not-Yet MeaningA1 — Use chưa to say that an expected action or state has not been reached by the relevant time.
- Negating Modal ExpressionsB2 — Control scope with không, chưa, and Vietnamese modal expressions such as có thể, phải, nên, cần, and được.
- Double NegationB1 — Interpret Vietnamese double negatives as logical reversal, emphatic necessity, or pragmatic understatement rather than automatic negative concord.
- Aspect Scope under Negation and QuestionsC2 — How Vietnamese negation and question frames target occurrence, completion, experience, continuation, and viewpoint.
- Rồi versus XongB2 — Distinguish post-predicate rồi, which updates the discourse to a new state, from xong, which says that a bounded task reaches its endpoint.