Biết: Know Facts and Know How

Vietnamese biết expresses having information, being aware of a person or thing, or possessing the knowledge or skill needed to perform an action. It can introduce a noun phrase (biết địa chỉ “know the address”), a proposition (biết anh ấy đã về “know that he has returned”), or another predicate (biết bơi “know how to swim”). The form biết itself does not conjugate.

English uses know for several relations that Vietnamese may distinguish more carefully. Biết is not the same as hiểu “understand,” and knowing a person exists is not always the same as being personally familiar with them, for which quen may be more precise. This page maps biết and leaves interpretation and comprehension to the dedicated page on hiểu.

Construction map

The complement determines the relation. There is no productive paradigm like know/knew/known. Đã biết, từng biết, mới biết, and biết rồi locate or frame the state of knowledge without altering the headword. Because bare biết is normally stative, đang biết is generally not used for the ongoing possession of knowledge; use đang tìm hiểu when the intended meaning is an activity such as “currently learning about.”

Knowing information and facts

With a noun phrase, biết means possess the relevant information or awareness. Common objects include tên “name,” địa chỉ “address,” lý do “reason,” tin này “this news,” and chuyện đó “that matter.”

A full clause can follow directly: Tôi biết bạn đang lo “I know you are worried.” Rằng may introduce a proposition in more explicit, careful, or formal prose—Tôi biết rằng quyết định này không dễ—but it is usually optional after biết, especially in conversation.

Question-word clauses work without English-style reordering: biết anh ấy ở đâu “know where he is,” biết khi nào tàu đến “know when the train arrives,” biết ai gọi “know who called.” The question word remains where the missing information belongs.

Knowing how: biết + predicate

Before another predicate, biết commonly means have the learned knowledge or skill to perform it. Vietnamese does not need an equivalent of English how to: biết bơi “know how to swim,” biết nấu ăn “know how to cook,” biết dùng máy này “know how to use this machine.”

This frame can shade into appropriate judgment: biết giữ lời “know to keep one’s word / be someone who keeps promises,” biết lắng nghe “know how to listen,” and biết nghĩ cho người khác “be considerate enough to think of others.” The speaker evaluates not only technical ability but socially appropriate conduct.

Do not insert cách mechanically. Biết cách + predicate is possible and focuses on knowing the method: biết cách mở khóa “know the way to open the lock.” Plain biết mở khóa is more compact and usually enough for practical ability.

Knowing people, places, and names

Biết + person/place can mean know of, be aware of, or have some acquaintance with. The strength of the relationship is context-dependent. Quen more clearly expresses familiarity or an established acquaintance, while biết đến often means know of or become aware of.

Compare Tôi biết ca sĩ đó “I know/know of that singer” with Tôi quen ca sĩ đó “I am acquainted with that singer.” English know leaves this distinction implicit; Vietnamese lets the speaker choose how much familiarity to assert.

Biết mặt means recognize someone by sight, biết tên know the name, and quen mặt be familiar-looking. These are useful when “know someone” would otherwise overstate the relationship.

Coming to know: mới biết, biết được, and biết rồi

Knowledge is a state, but Vietnamese can foreground its beginning. Mới biết means have just learned or only then realize. Biết được often means manage to learn, find out, or gain access to information. Biết rồi means know already/now know, and in response to repeated instructions it can sound impatient (informal).

Đã biết can simply locate knowledge before now or signal “already know.” Unlike a completed action, knowing may continue. Từng biết can mean once knew or once was acquainted with, often implying that the knowledge or relationship no longer holds fully.

Negation, ignorance, and indirect questions

Không biết means not know. It also introduces a polite or tentative question: Không biết anh có rảnh không? literally says the speaker does not know whether the addressee is free, and pragmatically asks. This is neutral-polite rather than a denial requiring an answer first.

Chưa biết means not know yet, often leaving open that information will become available. Đâu biết or biết đâu must be distinguished. Tôi đâu biết is an emphatic conversational denial, “How would I know?/I didn’t know” (informal). Biết đâu + clause means “perhaps/you never know,” presenting an uncertain possibility (informal/neutral).

Biết versus hiểu

Biết answers whether information or ability is present. Hiểu answers whether the meaning, logic, or motivation is comprehended. A learner may biết quy tắc “know the rule” but not hiểu tại sao có quy tắc đó “understand why that rule exists.”

Likewise, biết anh ấy buồn is awareness of the fact; hiểu vì sao anh ấy buồn is comprehension of its reason. English often uses understand and know flexibly, but Vietnamese construction choice can make the distinction explicit.

Fixed combinations and register

Biết ơn means be grateful; ơn is essential, and the combination is not simply factual knowledge. Biết điều describes someone as sensible, considerate, or aware of proper behavior (informal/neutral, sometimes judgmental). Biết bao is an expressive or literary quantifier meaning “how much/how many” (literary/formal), as in biết bao kỷ niệm “so many memories.”

These expressions should be learned whole. A dictionary list that treats each as just another translation of know hides their grammar and register.

Minimal five-way contrast

Information is not the same as comprehension

Biết cách dùng asks about practical know-how. The answer identifies abilities with bare predicates after biết. Chưa hiểu then marks the remaining gap: the speaker can perform steps without comprehending the underlying system.

Common Mistakes

1. Translating “know how to” word for word. Vietnamese normally places the action directly after biết.

2. Using biết for comprehension. Awareness of words or facts does not guarantee understanding.

3. Using quen when only awareness is intended. Quen implies familiarity; biết/biết đến can report merely knowing of someone.

4. Treating nghe nói as established knowledge. Reported information becomes biết chắc only after adequate confirmation.

Key Takeaways

• Biết + noun/clause expresses factual knowledge or awareness.
• Biết + predicate expresses know-how or a socially valued ability, without an obligatory equivalent of English how to.
• Biết may mean know of a person; quen more clearly asserts familiarity or acquaintance.
• Mới biết, biết được, and biết rồi frame the acquisition or current relevance of knowledge.
• Keep biết “know” distinct from hiểu “understand” and nghe nói “hear reported information.”