Vamos separar o papelão do plástico.

Here, vamos + infinitive means let’s ... in English.

So:

• Vamos separar = Let’s separate

Even though vamos literally comes from the verb ir (to go) and by itself means we go or we are going, in this structure it works like a suggestion or invitation:

• Vamos comer. = Let’s eat.
• Vamos sair. = Let’s go out.

So in this sentence, vamos separar is not mainly about movement; it is saying let’s do this.

Because after vamos in this kind of suggestion, Portuguese uses the infinitive.

Pattern:

• Vamos + infinitive

Examples:

• Vamos estudar. = Let’s study.
• Vamos limpar a casa. = Let’s clean the house.
• Vamos separar o papelão do plástico. = Let’s separate the cardboard from the plastic.

This is very common in everyday Brazilian Portuguese.

Yes, separar is very similar to English to separate.

In this sentence, it means to sort apart / to separate one material from another.

A very common pattern is:

• separar X de Y = to separate X from Y

So:

• separar o papelão do plástico = to separate the cardboard from the plastic

This is especially common in contexts like recycling, organizing, sorting laundry, or dividing objects.

Do is a contraction of:

• de + o = do

After separar, Portuguese often uses de to express from:

• separar X de Y = separate X from Y

So:

• do plástico literally = de o plástico
• natural English meaning here = from the plastic

Important point: even though de often means of, in this sentence it is best understood as from, because of the verb separar.

Because Portuguese usually uses definite articles more often than English.

• o papelão = the cardboard
• o plástico = the plastic

In English, we often leave out the article in general statements, especially with materials:

• cardboard
• plastic

But Portuguese often keeps the article:

• o papelão
• o plástico

So even if English says Let’s separate cardboard from plastic, Portuguese naturally says Vamos separar o papelão do plástico.

Because Portuguese often uses the singular when talking about a material or substance in a general sense.

So:

• o papelão = cardboard as a material
• o plástico = plastic as a material

This is similar to English, where we also often use mass nouns:

• cardboard
• plastic

If you were talking about specific items, the plural could appear in another sentence, but here the singular sounds natural because the focus is on the materials.

No. Papelão means cardboard, not ordinary paper.

Compare:

• papel = paper
• papelão = cardboard

The ending -ão changes the word, and here it refers to the thicker material used in boxes and packaging.

So:

• uma folha de papel = a sheet of paper
• uma caixa de papelão = a cardboard box

A rough pronunciation guide is:

• pa-pe-LÃO

The stress is on the last syllable because of the accent mark.

The ending -ão is a nasal sound, which can be tricky for English speakers. It is not pronounced like English ow. It is more like a nasalized ow/ung sound, but the exact sound is best learned by listening to native speakers.

A rough English-friendly approximation might be:

• pah-peh-LOW̃

But remember that the final sound is nasal.

The accent mark shows the stressed syllable:

• PLÁS-ti-co

Without getting too technical, the accent tells you that the stress is on plás.

This helps both with pronunciation and spelling.

A rough guide is:

• PLAS-chee-coo in many Brazilian accents

A few notes:

• The stress is on the first syllable: PLÁS
• In many parts of Brazil, ti before a vowel can sound like chee
• The final o is often pronounced more like oo in casual Brazilian speech

So a rough approximation could be:

• PLAS-chee-koo

But pronunciation varies somewhat by region.

Sometimes vamos + infinitive can literally mean we are going to ..., but in many everyday situations it means let’s ....

Context matters.

For example:

• Vamos sair agora. can mean Let’s leave now.
• In another context, vamos sair amanhã might be understood as We’re going to leave tomorrow

In Vamos separar o papelão do plástico, the most natural reading is usually Let’s separate the cardboard from the plastic, especially if someone is suggesting an action.

Sometimes yes, but Vamos separar o papelão do plástico sounds very natural and standard.

If you remove the articles:

• Vamos separar papelão de plástico

that can sound less natural in many contexts, or more abstract depending on what you mean.

Portuguese often prefers the articles with nouns like these, especially in ordinary speech.

So for a learner, keep the articles here.

Both are grammatically possible. The choice depends on what you present as the first item.

• separar o papelão do plástico = separate the cardboard from the plastic
• separar o plástico do papelão = separate the plastic from the cardboard

The meaning is very similar, but the first noun is the thing you mention first as the item being separated.

Yes, very much so.

This kind of sentence is exactly the kind of thing you might hear when talking about:

• recycling
• sorting trash
• organizing materials
• separating packaging before disposal

Related words you might also see are:

• vidro = glass
• metal = metal
• lixo = trash
• reciclagem = recycling

So this sentence sounds very natural in real-life Brazilian Portuguese.

Yes. A few natural alternatives are:

• Vamos separar o papelão do plástico.
• Vamos separar o papelão e o plástico.
• Vamos separar o lixo reciclável.

There are slight differences:

• separar o papelão do plástico emphasizes separating one material from the other
• separar o papelão e o plástico can sound more like sorting both items into separate groups
• separar o lixo reciclável is broader: separate the recyclable trash

Your original sentence is very clear and natural.