Negation in Vietnamese

In Brief

Put không before a verb or adjective to mean “not”: Tôi không hiểu (“I don’t understand”) and Món này không cay (“This dish isn’t spicy”). Use không phải (là) before a noun or identity, chưa for “not yet,” and đừng for a negative command: “don’t.”

Overview

Negation lets you say that an action does not happen, a description is not true, something is absent, or an action should not be done. It is an A1 foundation in Vietnamese, and the basic word order is reassuringly regular: the negative word normally comes directly before the verb or adjective it affects.

Vietnamese verbs do not conjugate—that is, they do not change form to match the subject or tense. English changes “do” to “does” and adds an auxiliary in “she does not know”; Vietnamese simply puts không before the unchanged verb: Cô ấy không biết. The subject can change, but biết stays the same.

The main choice is not a verb ending but the type of meaning. Use không for a general negative, chưa when something has not happened up to now, không phải (là) to reject a noun-based identity or classification, and đừng when telling someone not to act. Learning these contrasts prevents most beginner errors.

How It Works

The beginner map

Meaning	Basic pattern	Example	Translation
not + action	subject + không + verb	Tôi không ăn thịt.	I don’t eat meat.
not + quality/state	subject + không + adjective	Cà phê không nóng.	The coffee isn’t hot.
not + noun/identity	subject + không phải (là) + noun phrase	Anh ấy không phải là bác sĩ.	He isn’t a doctor.
not yet	subject + chưa + verb/adjective	Tôi chưa xong.	I’m not finished yet.
not have/exist	không có + noun	Tôi không có xe.	I don’t have a vehicle.
don’t!	đừng + verb	Đừng lo.	Don’t worry.

A subject is the person or thing being discussed. A verb expresses an action or state, and a noun names a person, thing, place, or idea. Vietnamese often allows the subject to be left out when the situation makes it obvious, as in Chưa sẵn sàng (“Not ready yet”).

Không before a verb

For an ordinary negative statement, place không before the verb. Nothing is added after the verb, and there is no equivalent of English “do/does.”

• Tôi hiểu. — I understand.
• Tôi không hiểu. — I don’t understand.
• Lan uống cà phê. — Lan drinks coffee.
• Lan không uống cà phê. — Lan doesn’t drink coffee.

Time usually comes from context, a time expression, or an aspect marker (a word showing how an event unfolds). Thus Tôi không đi can mean “I don’t go,” “I’m not going,” or, in the right context, “I won’t go.” More explicit versions include Hôm qua tôi không đi (“I didn’t go yesterday”) and Ngày mai tôi không đi (“I’m not going tomorrow”).

Không before an adjective

Vietnamese adjectives can serve directly as the sentence’s predicate—the part that says something about the subject. English needs a form of “be” in “the room is clean,” but Vietnamese says Phòng sạch. Negation follows the same direct pattern:

• Phòng này không sạch. — This room isn’t clean.
• Tôi không mệt. — I’m not tired.
• Món này không đắt. — This dish isn’t expensive.

Do not insert là before an ordinary adjective. Tôi không là mệt is not the normal way to say “I’m not tired”; use Tôi không mệt.

Không phải (là) before a noun or identity

When the positive statement classifies or identifies something with a noun phrase, the negative is không phải (là). Compare an adjective with a noun:

Type	Positive	Negative
adjective	Cô ấy vui. (She is happy.)	Cô ấy không vui. (She isn’t happy.)
noun identity	Cô ấy là giáo viên. (She is a teacher.)	Cô ấy không phải là giáo viên. (She isn’t a teacher.)

In this construction, là is often retained, especially when a full noun phrase follows: Đây không phải là vé của tôi (“This isn’t my ticket”). It may be omitted in natural speech: Anh ấy không phải bác sĩ. For a beginner, không phải là + noun phrase is a safe, clear model.

Nationality can be expressed as a noun identity. Tôi không phải là người Việt literally rejects the category “Vietnamese person” and means “I am not Vietnamese.”

Chưa: “not yet”

Use chưa when an action or state has not become true up to the relevant time, but it may become true later. It is not simply a more emphatic không.

With không	With chưa
Tôi không ăn. — I don’t eat / I’m not eating.	Tôi chưa ăn. — I haven’t eaten yet.
Cô ấy không đến. — She isn’t coming / doesn’t come.	Cô ấy chưa đến. — She hasn’t arrived yet.
Tôi không sẵn sàng. — I’m not ready.	Tôi chưa sẵn sàng. — I’m not ready yet.

In short answers, chưa can stand alone. If someone asks Bạn ăn chưa? (“Have you eaten yet?”), you can reply Chưa (“Not yet”). A common positive answer is Rồi (“Already / yes, I have”).

Không có: absence and possession

Có covers both existence (“there is/are”) and possession (“have”), depending on the sentence. Negate it as không có:

• Tôi không có tiền. — I don’t have money.
• Ở đây không có nhà vệ sinh. — There isn’t a restroom here.
• Hôm nay không có lớp. — There is no class today.

English uses different structures for “don’t have” and “there isn’t,” but Vietnamese uses không có in both.

Đừng: negative commands

Use đừng + verb to tell someone not to do something. An imperative is a command or request directed at another person.

• Đừng đi. — Don’t go.
• Đừng nói chuyện. — Don’t talk.
• Đừng lo. — Don’t worry.

Tone depends on context and voice. Adding xin can make a public or formal request more courteous: Xin đừng hút thuốc (“Please do not smoke”). Particles and forms of address can also soften everyday requests, but đừng + verb is the essential pattern.

Examples in Context

Vietnamese	English	Note
Tôi không hiểu.	I don’t understand.	không before a verb
Em không uống cà phê.	I don’t drink coffee.	The verb remains unchanged
Hôm qua chúng tôi không đi làm.	We didn’t go to work yesterday.	hôm qua supplies past time
Ngày mai anh ấy không đến.	He isn’t coming tomorrow.	ngày mai supplies future time
Món này không cay.	This dish isn’t spicy.	không before an adjective
Tôi không phải là người Việt.	I am not Vietnamese.	Negated identity
Đây không phải là điện thoại của tôi.	This isn’t my phone.	Rejecting identification
Cô ấy chưa đến.	She hasn’t arrived yet.	Expected event has not happened
Chưa sẵn sàng.	Not ready yet.	Subject omitted from context
Tôi chưa ăn sáng.	I haven’t eaten breakfast yet.	chưa rather than general không
Tôi không có tiền mặt.	I don’t have cash.	Negated possession
Gần đây không có ngân hàng.	There isn’t a bank nearby.	Negated existence
Đừng mở cửa.	Don’t open the door.	Negative command
Xin đừng chụp ảnh.	Please do not take photos.	Polite or public instruction
Tôi không còn sống ở Hà Nội nữa.	I no longer live in Hanoi.	“No longer” frame

Common Mistakes

Adding an English-style helping verb

• Wrong: Tôi làm không hiểu.
• Right: Tôi không hiểu.
• Why: Vietnamese does not build negatives with an equivalent of English auxiliary “do.” Put không directly before hiểu.

Using là with an ordinary adjective

• Wrong: Cô ấy không là mệt.
• Right: Cô ấy không mệt.
• Why: Adjectives such as mệt (“tired”) can be predicates by themselves. Là is not needed.

Negating a noun identity with only không

• Wrong: Anh ấy không bác sĩ.
• Right: Anh ấy không phải là bác sĩ.
• Why: To reject a profession, identity, or category expressed by a noun, use không phải (là).

Using không when “not yet” is intended

• Less accurate: Tôi không ăn sáng. for “I haven’t eaten breakfast yet.”
• Right: Tôi chưa ăn sáng.
• Why: Không can suggest that breakfast is not your habit or that you are not eating it. Chưa says it has not happened up to now.

Using không for a negative command

• Wrong: Không đi! when you mean a normal personal command, “Don’t go!”
• Right: Đừng đi!
• Why: Đừng + verb is the standard negative imperative. Bare không + verb can appear on signs, in prohibitions, or as a fragment, but it is not the best beginner model for addressing someone directly.

Translating every English “not” with the same word

• Wrong: Tôi không phải mệt.
• Right: Tôi không mệt.
• Why: The correct choice depends on what follows: không + adjective, but không phải (là) + noun phrase.

Usage Notes

Questions with không and chưa

The pattern có ... không? forms a neutral yes/no question: Bạn có nói tiếng Việt không? (“Do you speak Vietnamese?”). Here, the final không is part of the question frame, not simply the negative statement “not.” In everyday speech, có may be omitted: Bạn nói tiếng Việt không?

A negative question such as Bạn không đi à? means roughly “You’re not going?” It often signals surprise or checks an assumption. It is not as neutral as Bạn có đi không? (“Are you going?”).

With completed or expected events, ... chưa? asks “yet?”: Bạn làm xong chưa? (“Have you finished yet?”). The short replies Rồi (“Yes/already”) and Chưa (“Not yet”) are worth learning as a pair.

Subjects are often understood

Vietnamese may omit a subject when everyone knows who or what is meant. At a restaurant, Không cay can mean “Not spicy,” while Không có can mean “There isn’t any / I don’t have it,” depending on context. As a learner, include the subject when omission could create doubt.

Chẳng and chả

Chẳng is another negative word. It often feels more emphatic, expressive, or stylistically marked than neutral không: Tôi chẳng biết can mean “I have no idea” or “I really don’t know.” Chả is a common colloquial variant, especially associated with Northern speech. Neither is necessary for basic A1 communication; use không as your dependable default and learn chẳng/chả first for recognition.

Politeness comes from the whole sentence

A negative form is not automatically rude or polite. Pronouns, kinship terms used as forms of address, particles, and tone all matter. Đừng làm thế (“Don’t do that”) can sound firm; Xin đừng... is suited to courteous notices, while a fuller request may be gentler in conversation.

Beyond the Basics / Advanced Use

You do not need to master the following patterns at A1, but they make the basic system more precise.

“No longer”: không ... nữa and không còn ... nữa

To say that something used to be true but is not true now, use không ... nữa or the fuller không còn ... nữa:

• Tôi không làm ở đó nữa. — I don’t work there anymore.
• Cô ấy không còn ở đây nữa. — She is no longer here.

Còn contributes the sense of continuation or remaining, while nữa marks “anymore” in this negative frame.

Scope: what exactly is being denied?

Scope means the part of a sentence affected by the negative. Moving or expanding the phrase after không changes the focus:

• Tôi không mua sách. — I didn’t buy books / I don’t buy books.
• Không phải tôi mua sách. — It wasn’t me who bought the books.
• Tôi mua không phải sách mà là tạp chí. — What I bought was not a book but a magazine.

Context and spoken emphasis help listeners identify the intended contrast. Không phải ... mà (là) ... is a useful corrective frame: “not X, but Y.”

Softer and partial negatives

Vietnamese can qualify a negative rather than reject something completely:

• không hẳn — not exactly / not necessarily entirely: Điều đó không hẳn đúng (“That isn’t entirely true”).
• không nhất thiết — not necessarily: Không nhất thiết phải đi (“It isn’t necessary to go”).
• không bao giờ — never: Tôi không bao giờ hút thuốc (“I never smoke”).

These expressions behave as units and are best learned through complete sentences.

Aspect and past negatives

Vietnamese time and aspect markers require more context than English tense endings. Đã không commonly presents a past negative as a completed fact: Hôm qua tôi đã không đi (“Yesterday I did not go”). In many ordinary sentences, however, the time phrase is enough and đã is omitted: Hôm qua tôi không đi. Do not add đã mechanically every time English uses a past tense.

Prohibition with không được

Không được + verb expresses that an action is not allowed: Không được hút thuốc (“Smoking is not allowed / You must not smoke”). It is stronger and more rule-like than a simple request with đừng. Signs may also use compact forms such as Không hút thuốc (“No smoking”).

Practice Tips

1. Transform short positive sentences. Take five sentences such as Tôi hiểu, Cô ấy vui, and Đây là vé của tôi. Choose không or không phải là according to whether the key word is a verb/adjective or a noun phrase.
2. Make a không–chưa pair. For each verb, say one general negative and one “not yet” sentence: Tôi không ăn thịt versus Tôi chưa ăn sáng. This trains meaning, not just word order.
3. Listen for complete chunks. Save phrases such as không có, chưa xong, đừng lo, and không ... nữa. When watching Vietnamese media, note what comes immediately after each negative word and whether the subject is omitted.

Related Concepts

• Prerequisite: Basic Verb Structure — explains unchanged Vietnamese verbs, basic word order, and time/aspect markers that negation combines with.