A amortização reduziu a dívida.

They are both definite articles, meaning the.

• A amortização = the amortization / the repayment
• a dívida = the debt

Both amortização and dívida are feminine singular nouns, so the article is a in both cases.

Portuguese uses definite articles more often than English, especially when talking about specific things already understood from context.

Because nouns ending in -ção are almost always feminine in Portuguese.

Examples:

• a informação
• a situação
• a prestação
• a amortização

So the correct form is a amortização, not o amortização.

In financial Portuguese, amortização usually refers to the repayment of part of a loan or debt, often the part that reduces the principal still owed.

So it is more specific than a general pagamento. A pagamento is any payment; an amortização is a payment or accounting reduction that lowers the outstanding debt.

In this sentence, it means something like a repayment/amortization that made the debt smaller.

Not exactly.

• prestação usually means an installment: the regular amount you pay
• amortização refers more specifically to the part that reduces the debt itself, especially the principal

In many real contexts, one installment includes interest plus amortization. So they are related, but they are not the same word.

Reduziu is the pretérito perfeito simples of reduzir, in the 3rd person singular.

That means it describes a completed action in the past:

• A amortização reduziu a dívida = the reduction happened

If you said reduzia, that would suggest something ongoing, habitual, or backgrounded in the past:

• A amortização reduzia a dívida ao longo do tempo = it was reducing the debt over time

Because the subject is singular: A amortização.

In Portuguese, the verb agrees with the subject, not with the object.

Breakdown:

• A amortização = singular subject
• reduziu = singular verb
• a dívida = object

If the subject were plural, the verb would also be plural:

• As amortizações reduziram a dívida

The accent marks the stress: DÍ-vi-da.

Dívida is stressed on the third-to-last syllable, and words with that stress pattern are written with an accent in Portuguese.

So the accent is there to show the correct pronunciation and stress.

Normally, no.

In ordinary Portuguese, articles are usually kept with specific nouns:

• A amortização reduziu a dívida

Without the articles, the sentence sounds very telegraphic, like a headline, note, or technical shorthand. A learner should generally keep the articles unless there is a special reason not to.

Yes. This is the standard subject + verb + object order.

• A amortização = subject
• reduziu = verb
• a dívida = direct object

It is a very normal and neutral sentence structure in Portuguese.

You could also say it in the passive:

• A dívida foi reduzida pela amortização

But the original sentence is simpler and more direct.

Yes, you could say:

• A amortização diminuiu a dívida

That is grammatical and natural. However, reduzir often sounds a bit more precise or formal in financial language.

Also, be careful with the verb form:

• diminuir → diminuiu
• not diminuziu

A broad European Portuguese pronunciation is:

[ɐmuɾtizɐˈsɐ̃w ʁɨðuˈziw ɐ ˈdiviðɐ]

A rough English-friendly guide is:

uh-mor-ti-zuh-SOWN rdu-ZEE-oo uh DEE-vee-duh

A few useful points:

• amortização is stressed on the last syllable
• reduziu is stressed on ziu
• dívida is stressed on the first syllable
• unstressed vowels are often reduced in European Portuguese

With the definite article a, it usually sounds like a specific amortization/reduction already known from context.

So this sentence most naturally suggests:

• a particular repayment/amortization reduced the debt

If you wanted to express a general truth, Portuguese would often use the present tense:

• A amortização reduz a dívida

That means amortization reduces debt in a general sense.