A alfândega verificou a remessa.

In Portuguese, alfândega is a singular feminine noun. It refers to customs as an institution, office, or authority.

So:

• A alfândega = the customs office / customs authorities
• even though English uses the plural-looking word customs, Portuguese uses a singular noun

That is also why the verb is singular: verificou = it checked / inspected.

Here a means the.

Portuguese very often uses the definite article with nouns like institutions, places, and specific things. So:

• A alfândega = the customs
• not just customs in general, but the specific customs authority involved in the situation

This is very normal in Portuguese.

Verificou is the 3rd person singular of the preterite (in Portuguese grammar, pretérito perfeito simples) of the verb verificar.

So:

• verificar = to check / inspect / verify
• verificou = checked / inspected / verified

It describes a completed action in the past.

A quick mini-pattern for verificar in this tense:

• eu verifiquei
• tu verificaste
• ele/ela verificou
• nós verificámos
• vós verificastes
• eles/elas verificaram

In this sentence, the subject is A alfândega, so verificou is the correct form.

Not always.

This is an important point for English speakers: Portuguese verificar is often broader than English verify.

Depending on context, it can mean:

• to check
• to inspect
• to examine
• to verify

In a customs or shipping context, checked or inspected is often the most natural English translation.

So in this sentence, verificou does not necessarily mean that customs only confirmed some fact; it can also mean they examined the shipment.

Remessa is a fairly formal/logistics-related word. It usually means:

• shipment
• consignment
• dispatch

It is more technical than everyday words like:

• pacote = package
• encomenda = parcel / order

So a remessa sounds very natural in contexts such as:

• customs
• transport
• business
• freight
• shipping documentation

In everyday conversation, if you mean a normal parcel, people may more often say encomenda.

Because a remessa means the shipment, not just a shipment.

Portuguese commonly uses articles with specific nouns, including direct objects. Here the sentence is talking about a particular shipment already known in the context.

Compare:

• A alfândega verificou a remessa. = Customs checked the shipment.
• A alfândega verificou uma remessa. = Customs checked a shipment.

So the second a is also just the feminine singular definite article the.

Yes. It can refer to:

• the customs office as an institution
• the customs service
• the customs authorities / officials

In this sentence, A alfândega verificou a remessa, the most natural interpretation is the customs authorities checked the shipment.

This is similar to English, where customs can also mean either the institution or the officials working for it.

A practical pronunciation guide is:

A alfândega verificou a remessa.
approx. uh al-FAN-du-guh vuh-ree-fee-KOH uh ruh-MEH-suh

A few useful notes for European Portuguese:

• alfândega is stressed on fân
• verificou is stressed on the last syllable: cou
• remessa is stressed on me

More technical pronunciation (approximate IPA):

• alfândega: /aɫˈfɐ̃.dɨ.ɣɐ/
• verificou: /vɨ.ɾi.fiˈko/
• remessa: /ʁɨˈmɛ.sɐ/

Also, in European Portuguese, unstressed vowels are often reduced, so the sentence may sound more compressed than an English speaker expects.

The accent marks the stressed syllable: al-FÂN-de-ga.

Without getting too technical:

• the stress falls on fân
• the vowel before n is nasalized
• the accent helps show the correct stress pattern

So you should not say al-fan-DE-ga or AL-fan-de-ga. The stress is clearly on the middle part: fân.

Yes, Portuguese often allows the subject to be omitted when it is clear from context.

So if the context already made it obvious that you were talking about customs, someone might say:

• Verificou a remessa.

But on its own, that simply means He/she/it checked the shipment, and the listener would need context to know who did it.

That is why A alfândega verificou a remessa is clearer and more explicit.