Ban quản lý chưa biết nguyên nhân.

Ban quản lý means the management, the management board, or the administrators, depending on context.

• ban = a committee, board, section, or administrative unit
• quản lý = management / managing

Together, ban quản lý is a set phrase often used for an organization or body that manages something, such as:

• ban quản lý tòa nhà = the building management
• ban quản lý khu công nghiệp = the industrial park management board

In this sentence, it functions as the subject.

Vietnamese does not use articles like the, a, or an the way English does.

So Ban quản lý chưa biết nguyên nhân can naturally mean:

• The management doesn’t know the cause yet
• Management has not yet identified the cause

Whether it should be understood as the management or just management depends on context.

Chưa means not yet.

It shows that something has not happened up to now, but it may happen later.

So:

• chưa biết = does not know yet / has not found out yet

This is different from plain negation. It suggests an unfinished situation rather than a general or absolute no.

This is a very common question.

• không biết = do not know / doesn’t know
• chưa biết = do not know yet / hasn’t found out yet

So chưa adds the idea of yet.

Compare:

• Ban quản lý không biết nguyên nhân.
  = The management does not know the cause.
  This sounds more like a plain statement of ignorance.

• Ban quản lý chưa biết nguyên nhân.
  = The management does not know the cause yet.
  This suggests the information may become known later.

Vietnamese often follows a simple pattern like:

Subject + time/aspect/negation marker + verb + object

So here:

• Ban quản lý = subject
• chưa = aspect/negative marker meaning not yet
• biết = verb, to know
• nguyên nhân = object, the cause

That gives:

Ban quản lý / chưa / biết / nguyên nhân.

This word order is very natural in Vietnamese.

Biết mainly means to know. But in context, English may translate it more naturally as:

• know
• be aware of
• have identified
• have found out

In a sentence like this, especially in news or formal reporting, chưa biết nguyên nhân often implies:

• the cause is still unknown
• the cause has not yet been determined

So while the literal meaning is not yet know the cause, the natural English sense can be the cause has not yet been identified.

Both can be translated as reason, but they are not always used the same way.

• nguyên nhân = cause, often more objective, factual, or scientific
• lý do = reason, often used for explanation, motive, or justification

In this sentence, nguyên nhân fits better because it refers to the cause of an event, problem, accident, or situation.

For example:

• chưa biết nguyên nhân vụ cháy = the cause of the fire is not yet known
• lý do anh ấy đến muộn = the reason he came late

Grammatically, Vietnamese nouns usually do not change form for singular vs. plural the way English nouns do.

Ban quản lý refers to a collective body, so in English it could be rendered as:

• the management
• the management board
• sometimes the administrators

Vietnamese does not need to mark whether you are thinking of it as one unit or several people. Context handles that.

Yes, it sounds fairly neutral to formal, and it is especially natural in:

• news reports
• official statements
• administrative language
• reports about accidents, incidents, or investigations

It is less conversational than everyday speech like:

• Họ vẫn chưa biết nguyên nhân. = They still don’t know the cause.

So Ban quản lý chưa biết nguyên nhân sounds like something you might read in an article or hear in a report.

Yes. That is also natural.

• biết nguyên nhân = know the cause
• biết được nguyên nhân = manage to know / come to know / find out the cause

Adding được can make it sound a little more like successfully finding out or coming to know something.

So:

• Ban quản lý chưa biết nguyên nhân = The management does not know the cause yet.
• Ban quản lý chưa biết được nguyên nhân = The management has not yet been able to find out the cause.

The version without được is shorter and very common.

Yes. You can say:

Ban quản lý vẫn chưa biết nguyên nhân.

That means:

• The management still does not know the cause
• The management still has not identified the cause

Here, vẫn adds the idea of still, often emphasizing that some time has passed and the situation remains unchanged.

A rough guide is:

Ban quản lý chưa biết nguyên nhân
≈ bahn kwahn lee chuhh byet nwee-en nhun

A few useful notes:

• quản has a dipping/creaky tone
• lý has a rising tone
• chưa has a level-ish tone in the North
• biết has a rising, checked tone
• nguyên is usually pronounced roughly like ngwee-en
• nhân begins with nh, a sound somewhat like the ny in canyon

If you are learning pronunciation, it is best to listen to a native recording, because tones matter a lot more than English-style approximation.

It can stand alone grammatically, but in real use it often depends on prior context.

For example, listeners may already know:

• which management board is being discussed
• what event happened
• what cause is being referred to

So as a standalone sentence it is complete, but in actual communication it often follows earlier information such as a fire, accident, technical problem, or investigation.