Por favor, feche o portão antes de sair.

Feche is the command form used here.

In Brazilian Portuguese, when you give a command to você, the affirmative imperative usually matches the present subjunctive form. So:

• fechar = to close
• (que você) feche = that you close
• feche! = close! / please close

So Por favor, feche o portão is a polite command addressed to você.

A learner may also hear fecha o portão in everyday speech. That is common in informal spoken Brazilian Portuguese, but feche is the more standard form in careful grammar for a você command.

It is polite and fairly neutral, and it fits very well with você.

The clues are:

• Por favor = please
• feche = command form used with você
• o portão = normal direct object

So this sounds like a polite instruction such as:

• to a guest
• to a neighbor
• to a worker
• on a sign or notice

If you were speaking very casually, many Brazilians might say:

• Fecha o portão antes de sair.

If you were being more formally respectful with o senhor / a senhora, you could say:

• Por favor, feche o portão antes de sair, senhor.

Yes, por favor can go in different places.

In this sentence, it appears at the beginning:

• Por favor, feche o portão antes de sair.

That is very natural. But you can also say:

• Feche o portão, por favor.
• Feche, por favor, o portão antes de sair.

All of these are understandable. The most common and natural positions are usually:

• at the beginning
• at the end

So the placement here is normal and polite.

O is the masculine singular definite article, meaning the.

So:

• o portão = the gate

Portuguese uses articles more often than English does, so learners should get used to seeing them in many places.

Because portão is a masculine singular noun, it takes o:

• o portão = the gate
• um portão = a gate

If the noun were feminine, it would use a:

• a porta = the door

This is an important vocabulary point.

• porta = door
• portão = gate / large door, usually an outdoor entrance gate

So portão is used for things like:

• a front gate
• a driveway gate
• a building entrance gate
• a metal gate around a property

The ending -ão often gives the idea of something larger, though you should not rely on that as a universal rule for all words.

In this sentence, portão specifically suggests a gate, not an indoor door.

After antes, Portuguese normally uses de before an infinitive.

So:

• antes de sair = before leaving / before you leave

This is a very common structure:

• antes de dormir = before sleeping / before going to sleep
• antes de entrar = before entering
• antes de comer = before eating

So the pattern is:

• antes de + infinitive

That is why you get antes de sair, not just antes sair.

The subject is understood from context: it is the same person being addressed by the command.

So the full idea is:

• Please close the gate before you leave.

Portuguese often leaves the subject unstated when it is clear from context. Here, the sentence is speaking to you:

• feche = you close
• antes de sair = before leaving / before you leave

So even though você is not written, it is understood.

It can, but it usually doesn’t need to.

These two are possible:

• antes de sair = before leaving / before you leave
• antes de você sair = before you leave

The shorter version, antes de sair, is more natural when the subject is obvious and the same as the person already being addressed.

Using antes de você sair can add emphasis or clarity, but in this sentence it is unnecessary.

So the version in your sentence sounds smooth and natural.

It can mean both, depending on context.

Sair is a very common verb meaning:

• to leave
• to go out
• to exit
• to come out

In this sentence, the most natural English translation is:

• before leaving
• before you leave

Because the context is closing a gate, leave sounds more natural than exit, even though exit is not wrong in a more literal sense.

In standard Brazilian pronunciation, feche is roughly:

• FEH-shee

More precisely:

• fe sounds like feh
• ch sounds like sh
• final e is often pronounced like ee in many Brazilian accents

So:

• feche ≈ FEH-shee

This is only an approximation for English speakers, but it helps.

Also:

• portão has a nasal ending, something like por-TOWN with nasalization
• sair is roughly sah-EER

Pronunciation varies across Brazil, but these approximations are useful starting points.

Portuguese often omits subject pronouns when the meaning is clear.

So instead of saying:

• Você, por favor, feche o portão antes de sair.

Portuguese naturally says:

• Por favor, feche o portão antes de sair.

The verb form and context already show that the sentence is directed at you.

This happens all the time in Portuguese. English usually needs the subject, but Portuguese often does not.

Yes, but the verb form would normally change.

With você, the standard command is:

• Feche o portão.

With tu, the standard affirmative imperative would be:

• Fecha o portão.

However, Brazilian usage varies a lot by region. In some places, people use tu but do not always use the traditional tu verb forms consistently. Because of that, real-life spoken Brazilian Portuguese can be more mixed than textbook grammar suggests.

For a learner, the safest takeaway is:

• feche = standard command for você
• fecha = standard command for tu, and also common colloquially in some você contexts

Yes. In this sentence, antes de sair can naturally correspond to both:

• before leaving
• before you leave

English can choose either wording depending on style, but Portuguese uses the infinitive structure very naturally here.

That means antes de sair is compact and flexible. It does not sound incomplete to a Portuguese speaker.

Yes. A common alternative is por gentileza.

For example:

• Por gentileza, feche o portão antes de sair.

This also means please, but por favor is the most common and basic expression learners should know first.

In Brazil:

• por favor = very common, neutral, standard
• por gentileza = also polite, sometimes a bit softer or more formal in tone

So the original sentence is completely natural.

The base verb is fechar, meaning to close.

Some useful forms are:

• fechar = to close
• eu fecho = I close
• você fecha = you close
• ele/ela fecha = he/she closes
• feche! = close! (command to você)
• fechou = closed
• fechando = closing

So in your sentence:

• feche comes from fechar

This is useful because once you recognize the infinitive, you can connect the command form to the dictionary form more easily.