Vietnamese Verb "biết" — to know

biết

to know

Type

Cognitive verb

Patterns

6 tense/aspect forms

Simple / Bare Verb

The bare verb with no marker. Context determines whether it refers to present, past, or habitual action.

Simple statement

Structure: Subject + biết

Tôi biết.

I know.

Past / Completed (đã)

The marker "đã" before the verb explicitly marks a completed action or past event.

Completed marker: đã

Structure: Subject + đã + biết

Tôi đã biết.

I knew / I have known.

Progressive (đang)

The marker "đang" expresses an action currently in progress.

Progressive marker: đang

Structure: Subject + đang + biết

Tôi đang biết thêm.

I am getting to know more.

Future (sẽ)

The marker "sẽ" expresses a future action or intention.

Future marker: sẽ

Structure: Subject + sẽ + biết

Bạn sẽ biết.

You will know.

Negative (không / chưa)

"Không" negates the verb generally. "Chưa" means "not yet" — implying the action may happen later.

Negative marker: không

Structure: Subject + không + biết

Tôi không biết.

I don't know.

Not yet marker: chưa

Structure: Subject + chưa + biết

Tôi chưa biết.

I don't know yet.

Experience / Other (đã từng / vẫn)

"Đã từng" marks past experience ("have ever done"). "Vẫn" means "still" for ongoing states.

Experience marker: đã từng

Structure: Subject + đã từng + biết

Tôi đã từng biết nấu ăn.

I used to know how to cook.

Example Sentences

Tôi không biết.

I don't know.

Bạn có biết không?

Do you know?

Ai biết?

Who knows?