Vietnamese Negation with Không

The short version

Không goes before the action or quality you want to negate.

Pattern box

person + không + action/quality: Tôi không hiểu.

English trap

Do not put không at the end of a statement unless it is part of a question pattern.

Right vs wrong examples

Instead of this	Say this	Why
Copy the English structure word by word	Tôi không hiểu	Use the Vietnamese pattern as a ready-made chunk.
Add extra grammar words because English needs them	Tôi không ăn thịt	Vietnamese often stays shorter than English.
Study the rule without a real situation	Không cay	Attach the rule to a cafe, taxi, hotel, market, or work sentence.

Core examples

Vietnamese	English	Practice note
Tôi không hiểu	I do not understand	Không goes before the verb.
Tôi không ăn thịt	I do not eat meat	Keep the action after không.
Không cay	Not spicy	Short request at food stalls.
Không đường	No sugar	Useful drink request.
Không sữa	No milk	Drink customization.
Tôi không có tiền mặt	I do not have cash	Không có means do not have.
Tôi không biết	I do not know	High-frequency phrase.
Hôm nay không được	Today does not work	Soft refusal.
Phòng không sạch	The room is not clean	Không before adjective.
Tôi không nói được tiếng Việt	I cannot speak Vietnamese	Không plus nói được.
Không sao	No problem	Fixed polite phrase.
Không cần túi	No bag needed	Shop refusal.

How to use it in real sentences

Use the examples as sentence patterns, not isolated vocabulary. Say the whole line first, then replace one small part such as the person, time, object, or place.

Substitution drill

Base sentence	Change this	New sentence
Tôi không hiểu	change the person or topic	Tôi không ăn thịt
Tôi không ăn thịt	change the time, place, or object	Không cay
Không cay	say it as a real request or answer	Không đường

Real situation

Use this beginner foundation grammar when a real conversation forces you to speak quickly. Pick one sentence from the examples, imagine the situation, then change only one detail so the grammar becomes usable instead of abstract.

Southern Vietnamese note

Southern Vietnamese often prefers practical, context-rich examples. Learn the pattern through a line you might actually say.

Practice drill

1. Read each Vietnamese sentence aloud.
2. Replace one noun or time word.
3. Listen to the slow audio, then say the new sentence twice.
4. Cover the English and recall the Vietnamese from the situation.
5. Save the examples you would actually use this week.

Common mistake

Do not put không at the end of a statement unless it is part of a question pattern.

Next step

After this page, open the related practice or continue to the next grammar lesson: classifiers-cai-con.