How to say "I don't understand" in Vietnamese

"I don't understand" in Vietnamese is Tôi không hiểu (say "toy khohm hee-oo"). To sound polite, add xin lỗi (excuse me) at the start: Xin lỗi, tôi không hiểu.

That one sentence will get you far, but a few companion phrases make it much more useful. Here's how to say it, how to adjust it for different people, and what to say next.

Breaking down "Tôi không hiểu"

• Tôi means "I." It's neutral and polite, good with strangers.
• Không means "not" or "no."
• Hiểu means "understand."

So the sentence is literally "I not understand," which is how Vietnamese builds negatives: put không before the verb.

Pronunciation tips: hiểu has the hỏi tone (the hook mark), which dips and rises in Northern speech. In much of the South, the hỏi and ngã tones sound alike, so don't worry if you hear it said a bit differently. Không is often pronounced closer to "khom" with the lips closing at the end.

Choosing the right "I"

Vietnamese pronouns change depending on who you're talking to. Tôi is safe and neutral, but in many situations people use a family-style pronoun instead:

• Em không hiểu. If you're younger than the person, for example talking to an older shop owner or teacher.
• Con không hiểu. Talking to your parents, or to someone your parents' age in a family setting.
• Cháu không hiểu. Talking to someone your grandparents' or parents' age outside the immediate family.
• Mình không hiểu. Casual, with friends.

If you're not sure, tôi is fine. For more on choosing pronouns, see Vietnamese pronouns: anh, chị, em and how to choose.

Making it extra polite

Adding a polite particle at the start or end softens the sentence:

• Dạ, em không hiểu ạ. "Dạ" at the start and "ạ" at the end show respect, especially to elders.
• Xin lỗi, tôi không hiểu. "Sorry, I don't understand."

Polite particles like dạ and ạ do a lot of social work in Vietnamese. Our post on dạ and vâng, the polite yes explains them.

Saying you didn't hear clearly

Sometimes you understand the words; you just didn't catch them. Vietnamese has a separate phrase for that:

• Tôi nghe không rõ. "I didn't hear clearly." Nghe means "hear" or "listen," and rõ means "clear."

This is useful on the phone or in a noisy street, and it's gentler than saying you don't understand.

What to say next

"I don't understand" works best when you follow it with a request. These are the most useful:

• Bạn nói lại được không? Can you say that again?
• Bạn nói chậm lại được không? Can you speak more slowly?
• ... nghĩa là gì? What does ... mean? For example, "Phở tái nghĩa là gì?"
• Tiếng Việt nói thế nào? How do you say it in Vietnamese?
• Tôi chỉ biết một chút tiếng Việt. I only know a little Vietnamese.
• Bạn nói tiếng Anh được không? Can you speak English?

Swap bạn (you, for peers) for anh, chị, cô or chú depending on the person's age and gender. The pattern "... được không?" means "can you...?" or "is that okay?" and is worth learning by itself; see được không: how to ask is that okay.

Casual and regional versions

Among friends you'll hear shorter versions:

• Không hiểu. Just "don't understand," dropping the pronoun.
• Hông hiểu or hổng hiểu. In casual Southern speech, không often becomes hông or hổng. Use these only in relaxed situations.
• Chả hiểu gì cả or chẳng hiểu gì. "Don't understand anything at all." Chả and chẳng are other ways to say "not," heard widely, especially in the North.
• Ủa? A quick "huh?" when something surprises or confuses you. It's casual and very common, especially in the South.

A quick practice dialogue

Here's a short exchange you might have at a market:

• Seller: Cái này năm mươi nghìn. (This is fifty thousand.)
• You: Xin lỗi, tôi không hiểu. Chị nói chậm lại được không?
• Seller: Năm... mươi... nghìn.
• You: À, cảm ơn chị!

Notice how the request after "I don't understand" moves the conversation forward instead of stopping it.

Tips for using it confidently

• Smile and say it calmly. Most people are happy to help a learner.
• Use gestures, like pointing or writing numbers, alongside the words.
• Keep a note on your phone with your three favorite follow-up phrases.
• Don't over-apologize. One xin lỗi is enough.

Practise "Xin lỗi, tôi không hiểu. Bạn nói chậm lại được không?" out loud five times today so it comes out automatically when you need it.