Nós ficamos de montar o guarda-roupa no sábado, depois da faxina.

In Brazilian Portuguese, ficar de + infinitive is a very common expression meaning:

• to agree to do something
• to plan to do something
• to say you’ll do something later

So Nós ficamos de montar o guarda-roupa... means something like:

• We agreed to assemble the wardrobe...
• We said we’d put the wardrobe together...

It does not literally mean we stayed to here. This is an idiomatic use of ficar.

Other examples:

• Ficamos de conversar amanhã. = We agreed to talk tomorrow.
• Ele ficou de me ligar. = He said he’d call me.

Because ficamos de refers to the moment when the agreement was made, not the moment when the action will happen.

So the timeline is:

• first: we agreed
• later: we will assemble the wardrobe on Saturday

That is why Portuguese uses ficamos here. In English, we often do the same idea with:

• We agreed to assemble...
• We said we’d assemble...

The assembling is still in the future, but the agreement is already in the past.

Because after ficar de, Portuguese normally uses an infinitive verb.

Pattern:

• ficar de + infinitive

So:

• ficamos de montar
• ficou de ligar
• fiquei de mandar

Here, montar means to assemble / to put together.

This is similar to English structures like:

• agreed to do
• promised to call
• planned to send

Here montar means to assemble, to put together, or to set up.

Because the object is o guarda-roupa, the sentence most likely means assembling a piece of furniture, especially one that comes in parts.

Examples:

• montar um guarda-roupa = assemble a wardrobe
• montar uma mesa = assemble a table
• montar um computador = build/assemble a computer

So this is not about choosing clothes or organizing a closet. It is specifically about putting the wardrobe together.

Guarda-roupa means wardrobe, closet, or sometimes armoire, depending on context.

In Brazil, it usually refers to the furniture item used to store clothes.

About the form:

• guarda-roupa is a fixed compound noun
• it is commonly written with a hyphen

Plural:

• o guarda-roupa = the wardrobe
• os guarda-roupas = the wardrobes

So in this sentence, it most naturally means a wardrobe that needs assembling.

No sábado is the contraction of:

• em + o sábado = no sábado

In Portuguese, days of the week often appear with an article in expressions like this.

So:

• no sábado = on Saturday

This is very natural in Brazilian Portuguese.

You may also hear:

• sábado in certain contexts, especially in headlines or more compact speech
• but no sábado is the standard full form in everyday language

Examples:

• Vamos viajar no domingo. = We’re traveling on Sunday.
• Ele chega na sexta-feira. = He arrives on Friday.

Faxina means cleaning, especially a more thorough or house-cleaning type of cleaning.

In this sentence, depois da faxina means:

• after the cleaning
• after we finish cleaning up

Compared with other words:

• limpeza = a more general word for cleaning
• faxina = often suggests a practical, domestic, more intensive cleaning session

Examples:

• Fiz uma faxina no apartamento. = I did a big cleaning of the apartment.
• Depois da faxina, vamos descansar. = After cleaning, we’ll rest.

Because Portuguese contracts de + a into da.

So:

• de + a faxina = da faxina

This kind of contraction is extremely common.

Other examples:

• de + o = do
• em + a = na
• em + o = no
• por + a = pela
• a + a = à

So:

• depois da faxina = after the cleaning

This is just standard Portuguese grammar.

Yes. Portuguese often drops subject pronouns when the verb already makes the subject clear.

So these are both natural:

• Nós ficamos de montar o guarda-roupa no sábado...
• Ficamos de montar o guarda-roupa no sábado...

Because ficamos clearly shows we, the pronoun is not necessary.

Including nós can add:

• emphasis
• clarity
• contrast

For example:

• Nós ficamos de montar o guarda-roupa; eles ficaram de trazer as caixas.

In everyday Brazilian Portuguese, omitting nós is very common.

Both are possible, but a gente is very common in spoken Brazilian Portuguese.

So a very natural spoken version would be:

• A gente ficou de montar o guarda-roupa no sábado, depois da faxina.

Comparison:

• nós ficamos = a bit more neutral or slightly more formal
• a gente ficou = very common in everyday conversation

Important:

• a gente grammatically takes third-person singular verb forms:
  • A gente ficou
  • not A gente ficamos

So if you want the most conversational Brazilian Portuguese, a gente ficou de... is often what you will hear.

Yes. Depending on context, ficamos de + infinitive can carry slightly different shades of meaning, such as:

• we agreed to
• we planned to
• we were supposed to
• we said we would

So the exact English translation depends on tone and context.

For example:

• If both people actively made a plan: we agreed to
• If it was just a plan: we planned to
• If maybe they did not end up doing it: we were supposed to

That flexibility is normal. The core idea is that there was some prior arrangement or commitment.