Nós ficamos de desmontar o móvel velho antes de o entregador voltar.

It is an idiomatic structure. Ficar de + infinitive often means to agree to, to say you will, to arrange to, or to be supposed to do something.

So Nós ficamos de desmontar o móvel velho means something like We agreed to take apart the old piece of furniture or We said we would take it apart.

It does not mean the literal we stayed here.

Because the agreement/decision happened in the past.

Ficamos is the pretérito perfeito of ficar. It marks a completed past event: at some point, we agreed or we made the arrangement. The action of desmontar can still be in the future relative to that agreement.

So the timeline is:

• first: we agreed
• later: we would dismantle the furniture
• all of that: before the delivery person returns

They are very close, but not always identical in tone.

• combinamos de = we agreed/arranged to
• ficamos de = we said we’d / we were supposed to / we agreed to

Ficamos de can sometimes sound a little less formal and a little more like a prior understanding or commitment. In many everyday contexts, though, the difference is small.

Yes. In Brazilian Portuguese, subject pronouns are often omitted when the verb already makes the subject clear.

So Ficamos de desmontar o móvel velho... is perfectly natural.

Including Nós can add emphasis, contrast, or clarity, but it is not necessary here.

Here móvel is a noun, not an adjective. It means piece of furniture.

So o móvel velho means the old piece of furniture.

Depending on context, móvel could refer to a cabinet, wardrobe, shelf, table, or another furniture item. It is a general word.

Because in Portuguese, descriptive adjectives often come after the noun.

So:

• móvel velho = the furniture is old

That is the most neutral, standard order here.

You may also see adjectives before the noun in Portuguese, but that often adds style, emphasis, or a different nuance. With móvel, móvel velho is the normal choice.

When antes is followed by a verb, Portuguese normally uses antes de + infinitive.

Examples:

• antes de sair
• antes de comer
• antes de o entregador voltar

So antes de is the expected structure here.

This is a very common learner question.

In careful standard Portuguese, when the noun phrase is the subject of the infinitive, speakers and writers often avoid contracting de + o into do.

So:

• antes de o entregador voltar = standard, very safe choice

The reason is that o entregador is the subject of voltar.

You may hear antes do entregador voltar in casual speech, but antes de o entregador voltar is the form most textbooks and grammar explanations will recommend.

Because it is an infinitive. More specifically, this is an example of the personal infinitive, which Portuguese can use when an infinitive has its own subject.

Here the subject of voltar is o entregador.

In the 3rd person singular, the personal infinitive looks the same as the regular infinitive, so you see voltar.

This becomes clearer in the plural:

• antes de o entregador voltar
• antes de os entregadores voltarem

Notice how voltarem shows the personal infinitive more visibly.

Yes. That is also correct.

You have two common options:

• antes de o entregador voltar
• antes que o entregador volte

The first uses antes de + infinitive. The second uses antes que + subjunctive.

Both are natural. The infinitive version is often more compact and very common when the subject is expressed right there.

Grammatically, o entregador is masculine singular.

If the delivery person is female, you would usually say:

• a entregadora

If the person’s gender is unknown, many speakers still use the masculine form generically. Depending on the situation, someone might also choose a more neutral expression, such as a pessoa da entrega, but o entregador is very common in everyday Portuguese.

Yes. Desmontar is the natural verb when something is physically taken apart into pieces.

That makes it a very good choice for furniture:

• desmontar a cama
• desmontar o armário
• desmontar a mesa

So in this sentence, desmontar strongly suggests taking the furniture apart rather than just moving it.