O rendimento aumentou, de modo que amortizámos a dívida.

Here, rendimento most naturally means income, earnings, or revenue, depending on context.

A useful distinction:

• salário = salary/wages from a job
• rendimento = a broader term, which can include salary, investment income, rent, business income, etc.

So if the sentence is about personal finances, rendimento is broader than just salary.

The singular o rendimento often refers to overall income as one concept.

So:

• o rendimento = income as a whole
• os rendimentos = individual sources of income, earnings, or revenues

Both are possible in Portuguese, but the singular is very natural when talking about someone’s total income in a general way.

Aumentou is the pretérito perfeito of aumentar in the 3rd person singular.

It matches o rendimento, which is singular:

• o rendimento aumentou = the income increased

This tense is used because the increase is presented as a completed past event.

Compare:

• aumentou = increased
• aumentava = was increasing / used to increase
• tem aumentado = has increased / has been increasing

So aumentou is the normal choice if you are simply reporting what happened.

Here, de modo que introduces a result/consequence. It is equivalent to:

• so
• so that
• with the result that
• therefore

In this sentence, it means that the first fact led to the second one.

It is a bit more formal or written than everyday alternatives such as:

• por isso
• por isso mesmo
• assim
• então (depending on context)

So this sentence sounds natural, but a little more polished or formal than casual speech.

Because the sentence describes a real result that actually happened.

• de modo que amortizámos a dívida = the income increased, and as a result, we paid down the debt

The action of paying down the debt is presented as a fact, so the indicative is used.

Learners sometimes meet structures where de modo que can be linked to purpose, and then other verb forms may appear. But here it is clearly a consequence, so the indicative is the normal choice.

In European Portuguese, you will often see the 1st person plural preterite of -ar verbs written with an acute accent to distinguish it from the present form in writing.

So:

• amortizámos = we paid down / we amortised
• amortizamos = we pay down / we amortise

This is especially helpful because otherwise the two forms can look identical on the page.

Not exactly.

Pagar is the general verb to pay.

Amortizar, in financial language, means to pay down a debt, often by reducing the principal over time. It is more technical and more specific.

So:

• pagar a dívida = pay the debt
• amortizar a dívida = pay down the debt / amortise the debt

If you fully clear the debt, Portuguese might also use:

• liquidar a dívida
• saldar a dívida

Because Portuguese often omits subject pronouns when the verb ending already shows who the subject is.

Here, amortizámos already tells you the subject is we.

So:

• amortizámos a dívida = we paid down the debt

You could add nós, but it usually adds emphasis or contrast:

• Nós amortizámos a dívida, não eles.

Without emphasis, leaving out nós is the most natural choice.

Portuguese often uses the definite article where English would not.

Here, a dívida suggests a specific debt already known in the context: for example, a loan, mortgage, or some other debt the speaker and listener both know about.

So:

• a dívida = the debt

Without the article, dívida would sound less natural in an ordinary sentence like this, unless you were using a more telegraphic style, such as a headline or note.

Yes, it is very natural here.

The comma separates the main clause:

• O rendimento aumentou

from the result clause:

• de modo que amortizámos a dívida

In standard writing, this punctuation is appropriate and helps make the structure clear. Even if punctuation can sometimes vary, this comma is the normal choice in a sentence like this.

Not in this sentence as it stands.

De modo que is followed by a finite verb:

• de modo que amortizámos

But de modo a is followed by an infinitive:

• de modo a amortizar a dívida

That changes the structure and often the nuance:

• de modo que amortizámos a dívida = with the result that we paid down the debt
• de modo a amortizar a dívida = in order to pay down the debt

So de modo a usually expresses purpose, while de modo que here expresses result.