Eu vou guardar o recibo junto com o cartão.

Yes, you often can leave it out.

Portuguese verbs usually show who the subject is, so vou guardar already tells you the subject is I. That means:

• Eu vou guardar o recibo junto com o cartão.
• Vou guardar o recibo junto com o cartão.

Both are natural.

Speakers include eu when they want to:

• add emphasis,
• create contrast, or
• make the sentence clearer.

So eu is correct, but not always necessary.

Vou guardar is the very common near future structure in Portuguese:

• ir + infinitive
• vou + guardar

It works a lot like I’m going to keep/store... in English.

Portuguese also has a simple future form:

• Guardarei o recibo junto com o cartão.

But in everyday Brazilian Portuguese, vou guardar is much more common in normal speech. The simple future can sound more formal, written, or less conversational depending on context.

Guardar usually means to keep, to store, to put away, or to save depending on context.

In this sentence, it most likely means something like:

• keep
• put away
• store

So it suggests putting the receipt somewhere safe, probably with the card.

A few examples:

• Vou guardar esse documento. = I’m going to keep/put away this document.
• Guardei o dinheiro na gaveta. = I kept/put the money in the drawer.

It does not mean to guard in the English sense most of the time, even though the words are related.

O is the masculine singular definite article, meaning the.

So:

• o recibo = the receipt
• o cartão = the card

Portuguese uses definite articles more often than English does. In many everyday contexts, Portuguese prefers the where English might sometimes leave it out or choose a different wording.

Both nouns here are masculine singular, so they take o.

In Portuguese, nouns have grammatical gender. Here:

• recibo is masculine → o recibo
• cartão is masculine → o cartão

There is no perfect rule that always tells you a noun’s gender, but many nouns ending in -o are masculine. That helps with recibo.

For cartão, the ending -ão does not automatically tell you the gender, so it is something you learn with the article:

• o cartão

A very good habit is to learn nouns together with their article:

• o recibo
• o cartão

Junto com means together with.

So:

• o recibo junto com o cartão = the receipt together with the card

You could say just com in some situations, but junto com stresses that the two things will be kept together, in the same place or as a pair.

Compare:

• Vou guardar o recibo com o cartão. = I’ll keep the receipt with the card.
• Vou guardar o recibo junto com o cartão. = I’ll keep the receipt together with the card.

The second one makes the idea of keeping them together stronger and clearer.

Yes, absolutely. Junto com is very common and natural in Brazilian Portuguese.

You may also see:

• junto a in more formal or specific contexts, but for everyday speech, junto com is standard and widely used.

So this sentence sounds normal and idiomatic.

Yes, a little.

The original sentence is very natural:

• Eu vou guardar o recibo junto com o cartão.

You could also say:

• Eu vou guardar junto com o cartão o recibo.

But that version is less natural in most everyday situations.

The most common order is:

1. subject
2. ir in the present
3. infinitive
4. direct object
5. extra phrase

So the original order is the one learners should aim to use.

In cartão, the ã is nasal, which is very important in Portuguese pronunciation.

A rough guide:

• car sounds roughly like car
• tão has a nasal sound, something like town said through the nose, but not exactly

The accent mark ã shows nasalization.
Also, the stress falls on the last syllable:

• car-TÃO

That final -ão ending is very common in Portuguese and appears in many words, such as:

• pão
• mão
• informação

In Brazilian Portuguese, j usually sounds like the s in measure or the zh sound in vision.

So junto starts with that sound:

• ZHUN-to (roughly)

A few pronunciation notes:

• j = zh
• u is like oo in food
• to is short and clear

This is only an approximation, but it helps English speakers get close.

Sometimes, but usually a different verb is more common for digital contexts.

For physical objects, guardar is perfect:

• guardar o recibo
• guardar o cartão
• guardar o passaporte

For digital files, Brazilian Portuguese often prefers:

• salvar = to save
• armazenar = to store

For example:

• Vou salvar o arquivo. = I’m going to save the file.

So in your sentence, guardar sounds right because the objects are physical items.

By itself, cartão just means card. The exact type depends on context.

It could be:

• a credit card,
• a debit card,
• a bank card,
• a gift card,
• another kind of card.

If the speaker wants to be specific, they might say:

• cartão de crédito
• cartão de débito

In your sentence, o cartão is left general, so the listener understands it from the situation.

Not always. Recibo is a real and correct word, but Brazilian Portuguese also uses other words depending on the situation.

Common related words:

• recibo = receipt, proof of payment, acknowledgment of receipt
• comprovante = proof/confirmation, often proof of payment or transaction
• nota fiscal = official sales receipt/invoice, especially in stores and businesses

So recibo is correct, but in real life Brazilians may choose a different word depending on what kind of receipt they mean.

Yes, that is grammatically correct.

• Eu vou guardar... = everyday spoken Brazilian Portuguese, very common
• Eu guardarei... = simple future, more formal or less common in casual speech

Both are correct, but vou guardar sounds more natural in most everyday Brazilian conversation.

The sentence breaks down like this:

• Eu = subject
• vou = present tense of ir
• guardar = infinitive main verb
• o recibo = direct object
• junto com o cartão = prepositional phrase showing association

So the pattern is:

subject + ir (present) + infinitive + object + extra phrase

This is a very useful and common pattern in Brazilian Portuguese:

• Eu vou comprar pão.
• Ela vai estudar amanhã.
• Nós vamos guardar isso aqui.