The form ai does not always mean the question word “who.” With cũng, it forms a universal: ai cũng biết “everyone knows.” Within negation, it can form a negative indefinite: không ai biết “nobody knows.” Change the order and you change the scope: không phải ai cũng biết means “not everyone knows,” while ai cũng không biết distributes not-knowing over everyone.
English creates trouble here because everyone didn't come can be ambiguous or stylistically awkward. Vietnamese gives you clearer alternatives, but only if you choose the quantifier-negator order deliberately. This page focuses on person quantification. It leaves phrase-level focus such as “not Lan but Mai” to Constituent Negation and Contrast.
The core map
| Pattern | Meaning | Scope sketch |
|---|---|---|
| ai cũng + V | everyone V | ALL > V |
| không/chẳng ai + V | nobody V | NEG > ANY PERSON |
| chưa ai + V | nobody has V yet | NOT-YET > ANY PERSON |
| không phải ai cũng + V | not everyone V | NEG > ALL |
| ai cũng không + V | everyone does not V | ALL > NEG |
| ai mà chẳng + V? | who doesn't V? = everyone V | rhetorical universal |
This is not verb conjugation. The verb remains unchanged; the small words around ai determine whether the set is questioned, universal, empty, pending, or rhetorically exceptionless.
Ai cũng: a universal from a question word
In a content question, ai remains where a person-denoting answer would appear:
Ai phụ trách phần này?
Who is responsible for this section?
Add cũng, and the open variable becomes universal. Depending on context, English uses everyone, anyone, or whoever.
Trong nhóm này, ai cũng biết dùng phần mềm đó.
Everyone in this group knows how to use that software.
Món này dễ làm; ai cũng làm được.
This dish is easy to make; anyone can make it.
The relevant set comes from context: everyone in the group, anyone with the recipe, every invited person, and so on. Ai cũng does not literally quantify over every human being on earth.
Không ai and chẳng ai: an empty set
Place không before ai to say that no relevant person satisfies the predicate.
Không ai nhớ mã khóa cửa mới.
Nobody remembers the new door-lock code.
Khi tôi đến, chẳng ai ở văn phòng cả.
When I arrived, there was nobody in the office at all.
Không ai is neutral and suitable in all registers. Chẳng ai is more emphatic or stylistically colored; chả ai is common in casual speech (informal; especially Northern) and can sound dismissive. Formal prose usually favors không ai unless the rhetoric specifically calls for chẳng ai.
The predicate still follows the whole quantified subject. Do not insert another không unless you truly want double negation: không ai không biết means “everyone knows,” not “nobody knows.”
Chưa ai: nobody yet
Chưa ai V combines the empty-set effect with an open timeline. It says that, up to the reference time, no person has performed V, while leaving later performance possible.
Đến trưa vẫn chưa ai nộp đơn.
By noon, nobody had submitted an application yet.
Món này mới được mang đến nên chưa ai trong nhà ăn thử.
This dish was just brought in, so nobody in the family has tried it yet.
Compare không ai nộp đơn, which can report a completed outcome or a general fact. English often hides the distinction inside tense and yet; Vietnamese makes it in the negator.
Not everyone versus everyone not
The safest way to say “not everyone” is không phải ai cũng + V. The negative has scope over the universal, so some people may still satisfy the predicate.
Không phải ai cũng thích làm việc từ xa.
Not everyone likes working remotely.
Không phải ai cũng đã đọc email, nên mình nhắc lại nhé.
Not everyone has read the email, so let's repeat the announcement.
By contrast, ai cũng không + V assigns the negative predicate to every member of the set. In a clear context it means “everyone fails to V,” often equivalent in outcome to không ai V but with different information structure.
Hôm đó ai cũng không mang ô, nên cả nhóm bị ướt.
That day nobody in the group brought an umbrella, so the whole group got wet.
This wording foregrounds each member sharing the same negative property. Neutral không ai mang ô simply says the set of umbrella-bringers was empty. Because long sentences can create scope-processing difficulty, prefer không ai V when no distributive contrast is needed.
Rhetorical negatives that imply everyone
Questions such as Ai mà chẳng biết? literally ask “Who wouldn't know?” but conventionally imply that everyone knows. Mà helps mark the rhetorical stance; chẳng is not creating an empty set here.
Ai mà chẳng muốn được tôn trọng?
Who doesn't want to be respected?
Chuyện đó ai chẳng biết!
Everyone knows that!
These are expressive (informal to rhetorical), and intonation matters. They can sound impatient or dismissive. In a factual report, choose ai cũng instead.
Negation selects aspect and speech act
Quantifier scope operates inside the larger Vietnamese negative system:
| Form | Interpretation | Speaker's operation |
|---|---|---|
| không biết | do not know | neutral denial |
| chưa ăn | have not eaten yet | pending event |
| chẳng ai | nobody | empty human set, emphatic |
| đừng đi | do not go | negative directive |
| không phải là | is not / it is not that | corrective denial |
| đâu có quên | didn't forget! | contradiction of an assumption |
These choices cannot be collapsed into one English not. Chưa ai ăn says nobody has eaten yet; không ai ăn denies participation; đừng ai đi is possible only in marked directive contexts and tells the whole group that nobody should leave. More naturally, a speaker may say Mọi người đừng đi “Everyone, don't leave.”
Đâu có also changes the speech act:
Đâu có ai quên sinh nhật chị; mọi người đang bí mật chuẩn bị tiệc đấy.
Nobody forgot your birthday; everyone is secretly preparing the party.
The utterance does more than report a zero count: it rejects the listener's suspicion.
A dialogue where scope changes the head count
— Ai cũng đã xác nhận tham dự chưa? — Chưa; vẫn chưa ai bên phòng kế toán trả lời.
— Has everyone confirmed attendance? — Not yet; nobody from accounting has replied yet.
— Vậy không ai bên đó đến à? — Không phải ai cũng vắng. Chị Lan đã xác nhận rồi.
— So is nobody from that department coming? — Not everyone is absent. Ms. Lan has already confirmed.
— Còn nhóm kỹ thuật? — Hôm đó ai cũng không rảnh, nên họ xin họp trực tuyến.
— What about the technical team? — None of them is free that day, so they asked to meet online.
The first chưa ai describes a provisional zero. Không phải ai cũng vắng corrects the overly strong conclusion “everybody is absent.” The final ai cũng không rảnh distributes unavailability over every member of the technical team.
Common Mistakes
1. Translating ambiguous English “everyone didn't” without choosing scope.
❌ Ai cũng không đến.
Wrong if you mean ‘Not everyone came’; this normally gives every person the property of not coming.
✅ Không phải ai cũng đến.
Not everyone came.
The không phải ... cũng frame places negation over the universal while allowing some people to have come.
2. Adding a second không to “nobody knows.”
❌ Không ai không biết mật khẩu.
Wrong for ‘Nobody knows the password’; this means everyone knows it.
✅ Không ai biết mật khẩu.
Nobody knows the password.
Không ai already creates the intended negative quantifier.
3. Putting the negator after the verb.
❌ Ai biết không câu trả lời?
Incorrect for ‘Nobody knows the answer’; English-style placement does not form a Vietnamese negative subject.
✅ Không ai biết câu trả lời.
Nobody knows the answer.
4. Missing the not-yet meaning.
❌ Đến giờ không ai gửi bài.
Weak for the intended ‘nobody has submitted yet’: it does not explicitly present the zero count as provisional.
✅ Đến giờ vẫn chưa ai gửi bài.
So far, nobody has submitted the assignment yet.
Vẫn chưa ai makes the provisional timeline explicit.
5. Treating rhetorical ai chẳng as literal nobody.
❌ Ai chẳng cần nghỉ ngơi? — Không có ai cả.
Faulty interpretation: the rhetorical question does not expect ‘nobody.’
✅ Ai chẳng cần nghỉ ngơi? Ai cũng cần chứ.
Who doesn't need rest? Everyone does.
Key Takeaways
- Ai cũng V means everyone/anyone V; không ai V means nobody V.
- Chưa ai V describes a zero count that remains open to change.
- Không phải ai cũng V means not everyone; ai cũng không V distributes a negative over everyone.
- Ai mà chẳng V? is a rhetorical universal, not a literal request to identify a person.
- Choose the scope explicitly instead of copying ambiguous English quantifier order.
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Start learning Vietnamese →Related Topics
- Negative Polarity Items with Hề, Mấy, and GìB1 — Use hề, minimizing mấy, and indefinite gì inside Vietnamese negative environments to express ever, much, and anything.
- Constituent Negation and ContrastB2 — Negate a Vietnamese subject, object, reason, time, or description precisely with không phải, không phải là, and không X mà Y.
- Chẳng and Chả in ConversationA2 — Use chẳng and colloquial chả to make expressive negatives, and distinguish them from neutral không and aspect-sensitive chưa.
- Ai for WhoA2 — Ask who did, received, owned, or accompanied something while leaving ai in its ordinary noun-phrase position.