Hãy nhìn số tài khoản.

Hãy is an imperative marker. It helps make the sentence into an instruction or command, similar to please, do, or go ahead and in English depending on context.

So:

• Hãy nhìn số tài khoản. = Look at the account number.

In practice, hãy often sounds:

• a bit formal
• common in written instructions, teaching materials, speeches, or careful speech
• less common in casual everyday conversation than some other imperative patterns

It is not rude, but it can sound a bit formal or instructional.

A native speaker might use different forms depending on the situation:

• Hãy nhìn số tài khoản. → formal/instructional
• Nhìn số tài khoản đi. → more conversational
• Bạn hãy nhìn số tài khoản. → adds the subject you, slightly clearer
• Xin hãy nhìn số tài khoản. → more polite, like please look at the account number

So yes, it is acceptable, but it does not sound especially casual.

Vietnamese often omits the subject when it is already understood.

In an instruction, the listener is usually obviously the person being spoken to, so you does not have to be stated.

That means:

• Hãy nhìn số tài khoản.
• Bạn hãy nhìn số tài khoản.

can both mean basically the same thing, but the first one is more compact.

This is very normal in Vietnamese.

Nhìn means to look or to look at.

In this sentence, it means directing your eyes toward something:

• nhìn = look
• số tài khoản = account number

So the sentence is telling someone to look at the account number.

A useful comparison:

• nhìn = look at
• xem = look/watch/check/examine, often with more attention or purpose
• trông = look/appear, or look after in other contexts

In many real situations, a speaker might also say xem số tài khoản if they mean check the account number rather than just physically look at it.

This is a very common question.

nhìn

Focuses more on the act of looking with your eyes.

• Nhìn số tài khoản. → look at the account number

xem

Often means look at, check, review, or watch, depending on context.

• Xem số tài khoản. → check the account number

So:

• If the idea is simply direct your eyes to it, nhìn fits.
• If the idea is inspect/check it carefully, xem may sound more natural.

In actual banking or form-filling contexts, many speakers would probably prefer xem if they mean verify the number.

It breaks down like this:

• số = number
• tài khoản = account

So:

• số tài khoản = account number

This is a very common Vietnamese noun pattern:

• số điện thoại = phone number
• số nhà = house number
• số báo danh = candidate number / exam number

Because in Vietnamese, the word for number often comes before the noun it describes when talking about identification numbers.

So Vietnamese says:

• số tài khoản = account number
• số điện thoại = phone number
• số phòng = room number

This is just the normal word order for this kind of expression.

If you tried to say tài khoản số, it would not be the normal way to express account number.

Here, số means number as an identifier, not quantity.

Vietnamese số can have different meanings depending on context:

• số tài khoản = account number
• một số người = some people
• số lượng = quantity/amount

So in this sentence, số is clearly the identifying number of the account.

Not necessarily.

Vietnamese can use both patterns:

• nhìn số tài khoản
• nhìn vào số tài khoản

Both can work.

Difference:

• nhìn số tài khoản = look at the account number
• nhìn vào số tài khoản = look into/at the account number, with a slightly stronger sense of directing your eyes toward it

In many cases, vào is optional. Adding it can make the direction of the action feel a bit more explicit.

It is understandable and correct, but it may sound a little textbook-like or formal depending on context.

More natural alternatives in speech might be:

• Nhìn số tài khoản đi.
• Xem số tài khoản đi.
• Bạn nhìn số tài khoản này nhé.
• Bạn xem số tài khoản này đi.

If this appears in a lesson, manual, or instructions, Hãy nhìn số tài khoản. is perfectly fine.

A rough pronunciation guide for English speakers:

• Hãy ≈ like high but with a creaky/rising Vietnamese tone
• nhìn ≈ something like nyin, with the Vietnamese nh sounding like Spanish ñ
• số ≈ somewhat like saw or suh, but with Vietnamese vowel quality and tone
• tài ≈ like tie
• khoản ≈ roughly khwahn with a final stop-like ending feel

A few tone notes:

• hãy has the ngã tone
• nhìn has the huyền tone
• số has the sắc tone
• tài has the huyền tone
• khoản has the hỏi tone

The hardest parts for English speakers are usually:

• nh in nhìn
• the vowels in số and khoản
• getting the tones right

Yes. Very often it is left out.

Compare:

• Hãy nhìn số tài khoản. → look at the account number
• Nhìn số tài khoản. → look at the account number

The second one is shorter and often more natural in direct speech, though it can sound more blunt depending on context.

Vietnamese frequently uses just the verb for commands, especially in speech.

It is written as two separate syllables/words in standard Vietnamese spelling:

• tài
• khoản

Together they form the compound meaning account.

This is very common in Vietnamese: many single meanings are written as two separate written syllables, for example:

• điện thoại = telephone
• ngân hàng = bank
• học sinh = student

So even though it is written as two parts, you should learn tài khoản as one vocabulary item meaning account.