Eu posso pagar tanto no crédito quanto no débito.

Tanto ... quanto ... is a paired structure meaning both ... and ... or as much ... as ..., depending on context.

In this sentence, tanto no crédito quanto no débito means either by credit or by debit / both on credit and on debit.

It is a very common way to present two equivalent options.

Other examples:

• Ela fala tanto inglês quanto espanhol. = She speaks both English and Spanish.
• Aceitamos tanto pix quanto cartão. = We accept both Pix and card.

In your sentence, it emphasizes that both payment methods are possible.

Here, no is the contraction of em + o:

• em
  • o = no

So:

• no crédito = literally in/on the credit
• no débito = literally in/on the debit

In Brazilian Portuguese, when talking about card payment methods, people often say:

• pagar no crédito
• pagar no débito

This is the natural idiomatic way to say pay by credit card or pay by debit card.

You may also hear:

• pagar com cartão de crédito
• pagar com cartão de débito

Those are more explicit, but no crédito / no débito is extremely common in everyday Brazilian Portuguese.

Yes. In this context, crédito and débito are shorthand for cartão de crédito and cartão de débito.

So when someone says:

• É no crédito ou no débito? they mean:
• Will it be by credit card or debit card?

Native speakers often omit cartão because the context makes it obvious.

Yes, absolutely.

Portuguese often omits subject pronouns when the verb already makes the subject clear. Since posso clearly means I can, Eu is optional.

So both are correct:

• Eu posso pagar tanto no crédito quanto no débito.
• Posso pagar tanto no crédito quanto no débito.

Including Eu can add emphasis or clarity, but it is not necessary.

Because poder works like a modal verb, similar to can in English.

Structure:

• posso = I can
• pagar = pay

So:

• Eu posso pagar = I can pay

This is very common in Portuguese:

• Posso entrar? = Can I come in?
• Ela pode ajudar. = She can help.
• Nós podemos esperar. = We can wait.

After poder, the next verb normally stays in the infinitive.

No. It is natural, but not the only option.

Other common ways to express the same idea are:

• Eu posso pagar no crédito ou no débito.
• Posso pagar com crédito ou débito.
• Posso pagar no cartão de crédito ou no débito.

The version with tanto ... quanto ... sounds a little more balanced or emphatic, as if you are clearly presenting both options as acceptable.

If you just want the simplest everyday version, Posso pagar no crédito ou no débito? is extremely common.

In many real-life situations, the difference is small.

• ou = or
• tanto ... quanto ... = both ... and ... / either ... or ..., depending on context

Compare:

• Posso pagar no crédito ou no débito.
• Posso pagar tanto no crédito quanto no débito.

The first is a straightforward or statement.

The second gives a stronger sense that both options are available. It can sound a bit more explicit or polished.

In everyday conversation, both are natural.

Not usually by themselves in this context.

In Brazilian Portuguese, the most natural short forms are:

• no crédito
• no débito

If you want to use com, you normally say the full expression:

• com cartão de crédito
• com cartão de débito

So these are natural:

• Vou pagar no crédito.
• Vou pagar com cartão de crédito.

But vou pagar com crédito sounds less natural if you mean with a credit card.

It is understandable, but in a real store situation, a customer would more often say something like:

• Posso pagar no crédito ou no débito?
• Aceita crédito e débito?
• Vou pagar no débito.
• Pode ser no crédito?

Your sentence sounds a bit like I am able to pay either by credit or debit, which is grammatically fine, but in a normal interaction Brazilians often use shorter, more direct wording.

Débito is pronounced roughly like DEH-bee-too.

A few pronunciation notes:

• The stress is on the first syllable: DÉ-bi-to
• é is an open vowel, like eh
• The final o in Brazilian Portuguese is often pronounced like a short oo sound

Likewise:

• crédito is roughly KREH-jee-too in many Brazilian accents, because the d before i often sounds like j in English jam

So:

• crédito → KREH-jee-too
• débito → DEH-bee-too

Pronunciation varies a bit by region, but that will sound close.

The accent mark shows the stressed syllable and vowel quality.

• crédito → stress on cré
• débito → stress on dé

These are proparoxytone words in Portuguese, meaning the stress falls on the third-to-last syllable. In Portuguese, all proparoxytone words take a written accent.

So:

• crédito
• débito
• médico
• rápido

The accent helps you pronounce them correctly.

Not in the same structure.

In Brazil, you may hear passar when talking about running a card through the machine:

• Posso passar no crédito?
• Passa no débito, por favor.

Here, passar means something like run it as credit or debit.

But pagar is the more general verb meaning to pay:

• Posso pagar no crédito?

Both can be heard in stores, but they are not always interchangeable word-for-word. Pagar is safer for learners because it is more general and transparent.