Chị có thể cho tôi mượn thẻ không? Tôi muốn thanh toán, nhưng tôi không mang đủ tiền mặt.

Chị is a Vietnamese pronoun used for a woman who is slightly older than the speaker, or sometimes for a woman addressed respectfully in everyday speech.

So in this sentence, the speaker is talking to a woman and positioning her as an older female relative in social terms.

Why not bạn?

• bạn = friend / you in a more neutral, equal, often younger-style way
• chị = more socially aware and polite when speaking to a woman who is a bit older

Vietnamese pronouns depend heavily on age, relationship, and social context. English you does not show this, but Vietnamese usually does.

Tôi is a neutral, polite way to say I.

It is very common when:

• speaking politely
• speaking to someone you do not know well
• trying to sound respectful and not too intimate

In real conversation, Vietnamese often uses relationship-based pronouns instead of tôi. For example, a younger man speaking to an older woman might say em for I and chị for you.

So a more relationship-based version could be:

• Chị có thể cho em mượn thẻ không?

That often sounds more natural in everyday speech if the age relationship is clear.

Có thể means can / be able to / may.

In this sentence:

• chị có thể cho tôi mượn thẻ không? = Can you lend me the card?

A useful pattern is:

• [subject] + có thể + verb + không?
• Can [subject] ... ?

Examples:

• Bạn có thể giúp tôi không?
  Can you help me?
• Anh có thể đợi một chút không?
  Can you wait a moment?

So có thể expresses ability or possibility in a polite request.

Because cho mượn is the normal way to say lend.

Important distinction:

• mượn = borrow
• cho mượn = lend

So:

• Tôi mượn thẻ. = I borrow the card.
• Chị cho tôi mượn thẻ. = You lend me the card.

The structure is:

• cho + person + mượn + thing

So literally it is something like:

• let/give [someone] borrow [something]

That is why cho tôi mượn thẻ means lend me the card.

Thẻ usually means card.

Depending on context, it could be:

• a bank card
• credit card
• debit card
• membership card
• ID card
• access card

Because the next sentence mentions thanh toán and tiền mặt, the most natural interpretation here is a payment card, such as a bank card or credit card.

If you want to be more specific, Vietnamese can say:

• thẻ ngân hàng = bank card
• thẻ tín dụng = credit card
• thẻ ghi nợ = debit card

Here, không turns the sentence into a yes/no question.

Pattern:

• [statement] + không?

So:

• Chị có thể cho tôi mượn thẻ.
  You can lend me the card.
• Chị có thể cho tôi mượn thẻ không?
  Can you lend me the card?

This is one of the most common ways to ask polite yes/no questions in Vietnamese.

Note that không here does not mean simple negation by itself in the English sense of not. Its job here is to mark the question.

Yes, it is polite and common.

This pattern is softer than giving a direct command. Compare:

• Cho tôi mượn thẻ.
  Lend me the card.
  → very direct

• Chị có thể cho tôi mượn thẻ không?
  Can you lend me the card?
  → more polite

Vietnamese often softens requests with:

• có thể ... không?
• được không?
• giúp tôi ... được không?

So this sentence is framed as a polite request.

Thanh toán means to make a payment / settle a bill / pay.

It sounds a bit more formal or transactional than trả tiền.

Comparison:

• thanh toán = pay, make payment, settle payment
  often used in shops, hotels, bills, business contexts
• trả tiền = pay money
  very common, everyday, slightly more direct/basic

Examples:

• Tôi muốn thanh toán.
  I want to pay.
• Tôi muốn trả tiền.
  I want to pay.

Both can work here. Thanh toán sounds a bit more like the language of payment situations.

Because muốn means want to, and in Vietnamese it comes before the main verb.

Pattern:

• muốn + verb

So:

• Tôi muốn thanh toán.
  I want to pay.

More examples:

• Tôi muốn ăn.
  I want to eat.
• Tôi muốn đi về.
  I want to go home.

This is simpler than English in some ways, because Vietnamese does not need a separate to before the second verb in this structure.

Nhưng means but.

It connects two clauses:

• Tôi muốn thanh toán
• nhưng tôi không mang đủ tiền mặt

So the structure is:

• A, nhưng B
• A, but B

This works very much like English but.

Example:

• Tôi thích món này, nhưng nó đắt.
  I like this dish, but it is expensive.

Mang here means carry / bring / have on you.

In this sentence:

• tôi không mang đủ tiền mặt = I didn’t bring / I don’t have enough cash with me

About mang vs đem:

• both can often mean bring
• mang often feels like carry/have with you
• đem often emphasizes bringing something somewhere

In many everyday situations, the two overlap. Here mang is very natural because the speaker means they do not have enough cash on their person.

Đủ means enough / sufficient.

It comes before the noun:

• đủ tiền = enough money
• đủ thời gian = enough time
• đủ tiền mặt = enough cash

So:

• không mang đủ tiền mặt = not carrying enough cash

A useful pattern is:

• đủ + noun = enough [noun]
• không đủ + noun = not enough [noun]

Examples:

• Tôi không có đủ tiền.
  I do not have enough money.
• Chúng ta có đủ thời gian.
  We have enough time.

Because tiền mặt specifically means cash.

• tiền = money
• tiền mặt = cash
• tiền trong thẻ / tiền trong tài khoản = money in the card/account, not cash

The speaker is contrasting cash with payment by card. That is why tiền mặt is important here.

So:

• Tôi không mang đủ tiền mặt does not mean
• I have no money at all

It means specifically:

• I don’t have enough cash on me

Yes, Vietnamese sometimes omits repeated subjects when the meaning is obvious, but keeping tôi is perfectly normal and clear.

So both are possible:

• Tôi muốn thanh toán, nhưng tôi không mang đủ tiền mặt.
• Tôi muốn thanh toán, nhưng không mang đủ tiền mặt.

The full version with the second tôi is often better for learners because it is clearer and more explicit.

Grammatically, yes.

Socially, it depends on context. Asking to borrow someone’s payment card is a fairly big request, so it might sound unusual unless the people know each other well, such as family members or close friends.

So the Vietnamese itself is fine, but in real life this request is much stronger than something like:

• Chị có thể trả giúp tôi không? Tôi sẽ chuyển khoản lại.
  Could you pay for me? I’ll transfer it back.

That said, if the situation really is Can I borrow your card?, the grammar of the sentence is correct and natural.

Very often, yes.

In natural spoken Vietnamese, if you call the other person chị, you will often refer to yourself as em rather than tôi.

So a very natural everyday version would be:

• Chị có thể cho em mượn thẻ không? Em muốn thanh toán, nhưng em không mang đủ tiền mặt.

Why?

Because chị–em is a common pronoun pair:

• chị = older sister / slightly older woman / you
• em = younger sibling / younger person / I

Using tôi is still grammatical and polite, but chị–em often sounds warmer and more conversational.

Yes. That is also very common.

Compare:

• Chị có thể cho tôi mượn thẻ không?
• Chị cho tôi mượn thẻ được không?

Both mean roughly Can you lend me the card?

Difference in feel:

• có thể ... không? = focuses on ability/possibility, polite
• ... được không? = very common request pattern, often slightly more conversational

Both are useful and natural.

A simplified breakdown is:

Chị / có thể / cho tôi mượn / thẻ / không?

• subject
• modal expression
• verb phrase
• object
• question particle

Tôi / muốn / thanh toán, / nhưng / tôi / không mang / đủ tiền mặt.

• subject
• want
• verb
• but
• subject
• negative verb
• enough cash

So Vietnamese is often quite close to English word order here:

• subject + verb + object
• with modifiers like có thể, muốn, and không placed in predictable positions

That is one reason this sentence is fairly approachable for English speakers, even though the pronouns and request structure may feel unfamiliar.