Tôi biết / tôi không biết — Knowing people, facts and how to do things

What you will learn

Biết is a high-frequency Vietnamese word. It can express knowing a fact, knowing a person/place, or knowing how to do something. The English translation changes, but the Vietnamese pattern stays connected through the idea of knowledge or familiarity.

1. Tôi biết — I know

• Tôi biết. — I know.
• Em biết chỗ đó. — I know that place.
• Anh biết chị Lan. — I know Lan.
• Chị biết chuyện này. — I know about this matter.

2. Tôi không biết — I do not know

• Tôi không biết.
• Em không biết ở đâu. — I do not know where.
• Anh không biết tên. — I do not know the name.

Không biết is one of the most useful safe phrases for a learner. It is better to say you do not know than to guess.

3. Biết + question word

• Tôi không biết là ai. — I do not know who.
• Tôi không biết ở đâu.
• Tôi không biết tại sao.
• Anh biết mấy giờ không? — Do you know what time it is?

Question words can appear inside a larger statement rather than making the whole sentence an English-style inverted question.

4. Biết + action — know how to

• Tôi biết lái xe. — I know how to drive.
• Em biết nấu ăn. — I know how to cook.
• Anh biết nói một ít tiếng Việt. — I know/can speak a little Vietnamese.

In these structures, biết expresses acquired knowledge or ability.

5. Biết... không? — do you know...?

• Anh biết quán này không? — Do you know this place?
• Chị biết đường không? — Do you know the way?
• Em biết anh Nam không? — Do you know Nam?

As always, the exact social force depends on the relationship and tone.

6. A short conversation

Lan: Anh biết quán phở gần đây không?

David: Anh không biết. Ở đâu vậy?

Lan: Gần bưu điện.

David: Em biết đường không?

Lan: Biết. Để em chỉ.

7. Biết and hiểu are not the same

Compare:

• Tôi biết từ này. — I know this word / I am familiar with it.
• Tôi hiểu từ này. — I understand this word.

You can know that something exists without fully understanding it. B43 will focus on hiểu.

8. Biết rồi — I know now / I already know

Biết rồi. can mean “I know” or “I know already”, often with a sense that the information has been received.

Tone matters greatly. A calm Dạ, con biết rồi can be respectful; a sharp Biết rồi! can sound impatient.

9. Không biết nữa — I don't know anymore / I don't know

In some conversational contexts, không biết nữa can express uncertainty, giving up on an answer, or “I really don’t know”. Do not translate nữa mechanically from this one phrase; it has several uses later.

10. Useful vocabulary

• biết — know/be familiar with/know how to
• không biết — do not know
• biết rồi — know now/already know
• chuyện — matter/story/event, context-dependent
• lái xe — drive
• nấu ăn — cook
• chỉ — show/point/instruct; also has other meanings
• đường — road/way; sugar in another context

11. Vietnam in real life

Biết often appears in very short exchanges because the topic is already known: Biết không?, Biết., Không biết., Biết rồi. The words are few, but tone and context can make the social meaning quite different.

12. Common beginner mistakes

• Using biết whenever English uses “understand”.
• Thinking biết only means factual knowledge and missing its “know how to” use.
• Ignoring tone in a short phrase such as Biết rồi!.

Try it

1. Say “I don’t know.”
2. Say that you know how to cook.
3. Ask whether someone knows the way.
4. Give one example where biết and hiểu would not mean the same thing.

Quick recap

Biết covers knowledge, familiarity and knowing how to do something. Không biết is a core learner phrase, while hiểu belongs to the different idea of understanding.