A seguradora recebeu o relatório.

A is the feminine singular definite article, meaning the.

So a seguradora = the insurance company / the insurer.

It is capitalized here only because it is the first word of the sentence. In the middle of a sentence, it would be a seguradora.

Seguradora is a grammatically feminine noun, so it takes a.

In this sentence, it usually refers to an insurance company, and company names or company-type nouns often have grammatical gender in Portuguese. This is grammatical gender, not necessarily biological gender.

The masculine form would be o segurador, but that is a different form and may refer to the insurer in a more formal or personal sense depending on context.

O is the masculine singular definite article, meaning the.

So:

• o relatório = the report

The noun relatório is masculine, so it uses o. This is something learners simply need to memorize with the noun: o relatório, not a relatório.

Recebeu is the 3rd person singular preterite of receber.

That means it expresses a completed action in the past:

• receber = to receive
• recebeu = received

It matches the subject a seguradora, which is 3rd person singular.

Because recebeu is a conjugated verb, while recebido is the past participle.

In a full simple sentence, you usually need a conjugated verb:

• A seguradora recebeu o relatório. = correct

But recebido would normally need an auxiliary verb:

• A seguradora tinha recebido o relatório. = The insurance company had received the report.
• O relatório foi recebido pela seguradora. = The report was received by the insurance company.

So recebido cannot normally stand alone as the main verb here.

Because the verb agrees with the subject, not with every noun in the sentence.

Here:

• A seguradora = subject
• recebeu = verb
• o relatório = direct object

So the verb is singular because a seguradora is singular.

This works just like in English:

• The insurance company received the report.

The verb agrees with the insurance company, not with the report.

No. This is the most basic and common word order in Portuguese:

Subject + Verb + Object

• A seguradora = subject
• recebeu = verb
• o relatório = object

So the sentence structure is very straightforward and similar to English.

This is the difference between two past tenses:

• recebeu = preterite → a completed action
• recebia = imperfect → a repeated, ongoing, habitual, or background past action

So:

• A seguradora recebeu o relatório.
  = The insurance company received the report.
  A finished event.

• A seguradora recebia o relatório todos os meses.
  = The insurance company used to receive the report every month.
  A habitual past action.

In your sentence, recebeu is used because it refers to one completed act.

The acute accent in relatório shows where the stress falls and helps indicate vowel quality.

The stress is on tó:

• re-la-TÓ-rio

Without the accent, a learner might guess the stress incorrectly.

In Portuguese, accent marks are important because they often tell you how the word is pronounced and which syllable is stressed.

A careful learner-friendly approximation is:

uh seh-goo-ruh-DOR-uh ruh-suh-BEU oo ruh-luh-TO-ryoo

A few important European Portuguese points:

• Unstressed vowels are often reduced, much more than in Brazilian Portuguese.
• A at the start is usually a very short sound, like uh.
• recebeu is stressed on the last syllable: re-ce-BEU
• relatório is stressed on TÓ

If you want a more technical guide, a broad European Portuguese pronunciation is roughly:

[ɐ sɨɣuɾɐˈðoɾɐ ʁɨsɨˈbew u ʁɨlɐˈtɔɾju]

You do not need to reproduce that perfectly at first; the most useful thing is to get the stress right and reduce unstressed vowels.

In European Portuguese, you would normally use a clitic pronoun after the verb in an affirmative main clause:

• A seguradora recebeu-o. = The insurance company received it.

A few key points:

• o here means it and refers to o relatório
• it is attached to the verb with a hyphen: recebeu-o
• this verb-final placement is very typical of Portugal Portuguese

This is something that often surprises English speakers, because English keeps the object pronoun separate, while Portuguese often attaches it to the verb.