O vencimento desta parcela é na sexta-feira, então eu vou pagar antes da reunião.

In this sentence, vencimento means the due date or deadline for payment.

So O vencimento desta parcela means the due date of this installment.

A few related words:

• vencer = to expire / to be due
• data de vencimento = due date
• a conta vence na sexta-feira = the bill is due on Friday

In financial contexts, vencimento is very common in Brazilian Portuguese.

Parcela usually means an installment or payment portion.

In Brazilian Portuguese, it is often used when something is being paid in parts:

• pagar em parcelas = to pay in installments
• a primeira parcela = the first installment
• a última parcela = the last installment

So desta parcela means of this installment.

Because de + esta contracts into desta.

Common contractions like this are very important in Portuguese:

• de + o = do
• de + a = da
• de + este = deste
• de + esta = desta
• de + isso = disso

So:

• o vencimento de esta parcela → o vencimento desta parcela

Using the uncontracted form would sound unnatural.

Na is the contraction of em + a.

So:

• em a sexta-feira → na sexta-feira

In Portuguese, days of the week often appear with the article:

• na segunda-feira
• na terça-feira
• na sexta-feira

Here, é na sexta-feira means it is on Friday.

In Brazilian Portuguese, sexta-feira is the normal word for Friday.

The weekdays are:

• segunda-feira = Monday
• terça-feira = Tuesday
• quarta-feira = Wednesday
• quinta-feira = Thursday
• sexta-feira = Friday

In everyday speech, Brazilians often shorten them:

• na sexta = on Friday

So both of these are common:

• na sexta-feira
• na sexta

The full form is a bit more formal or neutral.

Both are possible, but they are structured differently.

This sentence says:

• O vencimento desta parcela é na sexta-feira
• literally: The due date of this installment is on Friday

A very common alternative is:

• Esta parcela vence na sexta-feira
• This installment is due on Friday

The version with vencimento sounds a bit more formal or administrative. The version with vence is often more direct and natural in everyday use.

Here, então means so, therefore, or in that case.

It connects the two ideas:

• the installment is due on Friday
• therefore, the speaker will pay before the meeting

So então eu vou pagar antes da reunião means:

• so I’m going to pay before the meeting

In conversation, então is extremely common and can have several uses depending on context.

Eu vou pagar is the very common spoken way to express the future in Brazilian Portuguese.

It is formed with:

• ir in the present + infinitive

So:

• eu vou pagar = I’m going to pay / I will pay

You could also say:

• pagarei

But pagarei sounds more formal, more written, or less common in everyday speech.

In modern Brazilian Portuguese, vou + infinitive is usually the most natural choice in conversation.

Not always. Portuguese often drops subject pronouns when the verb already makes the subject clear.

So both are possible:

• então eu vou pagar antes da reunião
• então vou pagar antes da reunião

Including eu can:

• add clarity
• add emphasis
• make the sentence flow more naturally in some contexts

In this sentence, eu is perfectly normal, but it is not strictly required.

Because da is the contraction of de + a.

The expression is:

• antes de = before

When de is followed by a reunião, it contracts:

• antes de a reunião → antes da reunião

So:

• antes da reunião = before the meeting

This kind of contraction is very common and usually required in natural Portuguese.

Not always, but very often.

Reunião means meeting or gathering. It can refer to:

• a work meeting
• a school meeting
• a family gathering
• an organized group meeting

In this sentence, because of the financial and scheduling context, many learners would naturally understand it as a meeting, probably a work or formal meeting.

Yes, it is natural and correct, especially in a somewhat formal or practical context.

It sounds like something someone might say when talking about bills, scheduling, or finances.

A few natural alternatives would be:

• Esta parcela vence na sexta-feira, então vou pagar antes da reunião.
• O vencimento da parcela é na sexta-feira, então eu pago antes da reunião.

But the original sentence is absolutely fine.

Reunião is pronounced roughly like heh-oo-nee-OWN, with the final ão nasalized.

Important points:

• reu is one syllable group
• ni is clear
• ão is a very common nasal ending in Portuguese

Words ending in -ão are everywhere in Portuguese:

• reunião = meeting
• informação = information
• situação = situation
• pagação is not a normal word, but pagamento is

For English speakers, the hardest part is usually the nasal sound in ão, because it does not really exist in the same way in English.

No. Even though reunião and reunion look similar, they are not used the same way.

In Portuguese:

• reunião usually means meeting
• reunion in the English sense is often more like reencontro or a specific kind of gathering

So in this sentence, antes da reunião should be understood as:

• before the meeting

This is a good example of a false friend learners should watch out for.