O ônibus vai sair da estação daqui a uma hora.

Because ônibus is one of those Portuguese nouns whose singular and plural have the same form.

• o ônibus = the bus
• os ônibus = the buses

So the article tells you whether it is singular or plural:

• o = singular
• os = plural

That is why the verb is vai and not vão here: o ônibus vai sair = the bus is going to leave.

Portuguese uses definite articles very often, more often than English does.

So o ônibus literally means the bus. In a sentence like this, it sounds natural because the speaker is referring to a specific bus, or to the bus being discussed.

In English, you sometimes omit articles in headlines or short notices, but in normal Portuguese sentences, the article is usually kept.

Vai sair is the very common everyday way to talk about the future in Brazilian Portuguese.

It is formed with:

• ir in the present: vai
• • the infinitive: sair

So:

• vai sair = is going to leave / will leave

You could also say:

• O ônibus sairá da estação daqui a uma hora.

That is correct, but it sounds more formal or written. In normal conversation, vai sair is much more common.

Literally, it means to leave from the station.

The verb sair often goes with de when you say where someone or something is leaving from:

• sair de casa = leave home
• sair do escritório = leave the office
• sair da estação = leave the station

So in this sentence, da estação tells you the point of departure.

Because de + a contracts in Portuguese:

• de + a = da

So:

• de a estação → da estação

This kind of contraction is extremely common:

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

So da estação simply means from the station.

It means one hour from now or in one hour.

This is a very common Portuguese time expression:

• daqui a
  • amount of time

Examples:

• daqui a dez minutos = in ten minutes
• daqui a dois dias = in two days
• daqui a um mês = in a month

So daqui a uma hora does not mean the trip lasts an hour. It means the departure will happen one hour from now.

Because hora is a feminine noun in Portuguese.

So you use feminine forms with it:

• uma hora = one hour
• duas horas = two hours

Not:

• um hora ❌

This is something you just have to learn with the noun: hora is feminine.

Sometimes you may hear em uma hora, but daqui a uma hora is the clearest and most standard way to mean one hour from now.

For a learner, it is best to remember:

• daqui a uma hora = one hour from now

Using daqui a avoids ambiguity and sounds very natural in Brazilian Portuguese when you are counting forward from the present moment.

Yes. Portuguese allows some flexibility.

The original sentence:

• O ônibus vai sair da estação daqui a uma hora.

You could also say:

• Daqui a uma hora, o ônibus vai sair da estação.

Both mean the same thing. The second version puts more emphasis on the time.

In everyday speech, both are natural.

A simple approximation for Brazilian Portuguese is:

• ônibus ≈ OH-nee-boos
• estação ≈ es-ta-SOWN

A couple of useful points:

• In ônibus, the stress is on the first syllable: Ônibus.
• The ô has a closed o sound.
• In estação, the stress is on the last syllable: estaÇÃO.
• The -ão ending is nasal, which is a very important Brazilian Portuguese sound.

So even if your pronunciation is not perfect yet, try to keep the stress in the right place:

• Ônibus
• estaÇÃO

No. Estação can mean different things depending on context, including:

• station
• season

Examples:

• estação de trem = train station
• estação de metrô = metro station
• estação do ano = season of the year

In this sentence, because of ônibus and sair, it clearly means a transport station.

A small note: in Brazil, for long-distance buses, people also often say rodoviária or terminal rodoviário. So in real life, you may hear:

• O ônibus vai sair da rodoviária daqui a uma hora.

Yes. A few alternatives are possible, depending on style and context:

• partir = depart
• deixar = leave

Examples:

• O ônibus vai partir daqui a uma hora.
• O ônibus vai deixar a estação daqui a uma hora.

But sair is very common, simple, and natural in everyday Brazilian Portuguese.

So for a learner, vai sair da estação is an excellent phrase to know.