Depois da chuva forte, os voos voltaram a sair do aeroporto.

Because da is the contraction of de + a.

• depois de = after
• a chuva = the rain
• de + a chuva → da chuva

So depois da chuva forte literally means after the heavy rain.

This kind of contraction is very common in Portuguese:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

In Portuguese, adjectives often come after the noun.

So:

• chuva forte = heavy rain
• literally, rain strong

You can sometimes place adjectives before the noun, but that often sounds more literary, emphatic, or changes the nuance. In normal everyday Brazilian Portuguese, chuva forte is the natural choice.

Portuguese often uses forte where English uses heavy.

So:

• chuva forte = heavy rain
• vento forte = strong wind
• calor forte can mean strong/intense heat

This is just a normal difference in collocation between the two languages.

The phrase Depois da chuva forte is an introductory time expression, and Portuguese often separates that kind of phrase with a comma.

So the sentence structure is:

• Depois da chuva forte, = time/background
• os voos voltaram a sair do aeroporto. = main statement

The comma helps readability and is very natural here. In shorter sentences, people sometimes omit this kind of comma, but using it is standard and clear.

Portuguese uses definite articles more often than English.

So os voos can mean:

• the flights
• or, depending on context, flights in general that the speaker has in mind

In this sentence, it most naturally refers to the flights from that airport, so os voos sounds very normal.

English often drops the article where Portuguese keeps it.

Voos is the plural of voo.

It is pronounced roughly like:

• VOH-os

There is a clear separation between the two o sounds.

Important spelling note:

• Older spelling used vôo
• Modern spelling is voo

This change came from spelling reform, so if you see vôo in older material, it is the same word.

Because the subject is os voos, which is plural.

• o voo voltou = the flight resumed / came back
• os voos voltaram = the flights resumed / came back

Portuguese verbs must agree with the subject in number and person, so plural subject → plural verb.

This is a very important structure:

voltar a + infinitive = to do something again or to resume doing something

So:

• voltaram a sair = started leaving again
• resumed departing

It does not mean they physically returned somewhere in order to leave. It is a set verbal pattern.

Other examples:

• Ela voltou a trabalhar. = She started working again.
• Começou a chover e depois parou, mas voltou a chover. = It started raining and then stopped, but it rained again.

Because the pattern is voltar a + infinitive.

Here:

• voltar = to return / to resume
• a sair = to leave, to depart

So voltaram a sair is the full structure.

This a is a preposition, not part of the infinitive itself.

Compare:

• começar a fazer = to start doing
• aprender a dirigir = to learn to drive
• voltar a funcionar = to start working again

Not necessarily. In this context, sair means to depart.

With transportation, sair de often means to leave from:

• O voo sai às 10h. = The flight leaves at 10.
• O ônibus sai da rodoviária. = The bus leaves from the bus station.

So os voos voltaram a sair do aeroporto means the flights resumed departing from the airport.

It does not focus on passengers walking out of the building. It refers to flight departures.

Because do is the contraction of de + o.

• sair de = to leave from
• o aeroporto = the airport
• de + o aeroporto → do aeroporto

So:

• sair do aeroporto = to leave from the airport

This is the same contraction pattern as da earlier in the sentence.

Voltaram is the preterite in Brazilian Portuguese.

Here it shows a completed event in the past:

• after the heavy rain, the flights resumed departures

That is why the preterite fits well.

Compare:

• voltaram = they resumed / they started again
• voltavam = they were resuming / they used to resume

In this sentence, voltaram is the natural choice because it describes a specific event that happened after the rain.

Yes. That would also be natural, but it is a slightly different structure.

• Depois da chuva forte = After the heavy rain
• Depois que a chuva forte passou = After the heavy rain passed

The original sentence uses a noun phrase:

• depois da chuva forte

The alternative uses a full clause:

• depois que a chuva forte passou

Both are correct. The original is shorter and more compact.

Yes, but the meaning shifts slightly.

• sair do aeroporto = to depart from the airport
• decolar = to take off

So:

• Os voos voltaram a sair do aeroporto focuses on departures operating again
• Os voos voltaram a decolar focuses more specifically on the planes taking off again

Both can work depending on what exactly you want to emphasize. The original sentence sounds very natural for general travel or airport news.