Depois da pausa, nós vamos voltar a trabalhar.

Because da is the contraction of de + a.

• depois de = after
• a pausa = the break/pause
• de + a pausa → da pausa

This kind of contraction is very common in Portuguese:

• de + o → do
• de + a → da
• em + a → na
• em + o → no

So Depois da pausa is the natural form.

Depois means after or later.

In this sentence, it appears in the expression depois de, which is a very common way to say after before a noun:

• depois da pausa = after the break
• depois do almoço = after lunch
• depois da aula = after class

You can also use depois by itself to mean later:

• A gente conversa depois. = We’ll talk later.

Because in Brazilian Portuguese, the structure ir + infinitive is extremely common for talking about the future.

So:

• nós vamos voltar = we are going to return / we will return

A more formal or literary version would be:

• nós voltaremos

Both are correct, but nós vamos voltar sounds much more natural in everyday spoken Brazilian Portuguese.

Voltar a + infinitive means to do something again or to go back to doing something.

So:

• voltar a trabalhar = to go back to work / to resume working

Other examples:

• voltar a estudar = to study again
• voltar a falar = to speak again
• voltar a tentar = to try again

In this sentence, the idea is that work stopped for a while and then starts again.

That a is part of the pattern voltar a + infinitive.

It is not an article, and it does not mean to in the same way English uses to before an infinitive. It is simply the preposition required by voltar in this structure.

So you learn it as a chunk:

• voltar a fazer
• voltar a trabalhar
• voltar a estudar

If you leave out the a, the sentence sounds wrong in standard Portuguese.

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

So these both work:

• Nós vamos voltar a trabalhar.
• Vamos voltar a trabalhar.

Both mean the same thing.
Including nós can add emphasis, clarity, or contrast, but it is not required here.

Yes, and in spoken Brazilian Portuguese that is often even more common than nós vamos voltar a trabalhar.

• nós vamos = more neutral/standard
• a gente vai = very common in conversation

Both mean we are going to go back to work.

Important difference:

• nós vamos
• a gente vai

Even though a gente means we, it takes a third-person singular verb.

The comma separates the introductory time expression from the main clause:

• Depois da pausa, nós vamos voltar a trabalhar.

This is very natural and helps readability.
In a short sentence, some people may omit the comma:

• Depois da pausa nós vamos voltar a trabalhar.

That is also understandable, but the comma is a good standard choice.

Yes. A very natural alternative is:

• Nós vamos voltar a trabalhar depois da pausa.

This version places the time expression at the end instead of the beginning.

Both are correct:

• Depois da pausa, nós vamos voltar a trabalhar.
• Nós vamos voltar a trabalhar depois da pausa.

The difference is mainly one of focus and style. Starting with Depois da pausa emphasizes the time.

Yes, intervalo could also work, depending on context.

• pausa = pause, break
• intervalo = break, intermission, interval

Pausa is broad and general.
Intervalo is especially common for breaks in school, events, shows, meetings, or work schedules.

So both can make sense:

• Depois da pausa...
• Depois do intervalo...

The best choice depends on the situation.

They are similar, but not always identical in tone.

• voltar a trabalhar suggests resuming work after an interruption
• trabalhar de novo means work again, but can sound a little more general

In this sentence, voltar a trabalhar is especially good because there was a break, and now the work will resume.

Normally, no. In this sentence, depois da pausa is the natural form.

Portuguese often uses articles where English does not. Here, a pausa refers to the break in a normal, definite way, so da is expected.

• natural: depois da pausa
• unnatural here: depois de pausa

For learners, it is best to remember depois de + article + noun when the noun normally takes an article.

In standard Brazilian pronunciation, trabalhar sounds approximately like trah-bah-LYAR.

A few helpful points:

• the lh in trabalhar is like the lli in million for many English speakers, though not exactly the same
• the stress falls on the last syllable: -lhar
• the final r in Brazil is often pronounced with a breathy h-like sound, depending on the region

So a rough learner-friendly pronunciation is:

• trah-bah-LYAH(h)

Yes, that is very close. Because the meaning has already been given, the important thing is the nuance:

• voltar a trabalhar emphasizes returning to work / resuming work
• work again is a possible translation, but it can sound slightly less specific

So the Portuguese strongly suggests that work had stopped and will now continue again after the break.