Retiro a certidão de nascimento no posto de atendimento.

Here retiro comes from the verb retirar.

In this sentence, retirar usually means to pick up, to collect, or to obtain from a place. So retiro a certidão de nascimento suggests I pick up / collect the birth certificate.

This is a very common verb in service situations, documents, tickets, orders, and official paperwork.

Retiro is the 1st person singular present tense form of retirar:

• eu retiro = I pick up / I collect
• você retira = you pick up
• retirar = to pick up

So the sentence is using eu retiro, but Portuguese often leaves out the subject pronoun eu because the verb ending already shows who the subject is.

Portuguese often omits subject pronouns when the verb form already makes the subject clear.

So:

• Eu retiro a certidão...
• Retiro a certidão...

both mean the same thing: I pick up the certificate...

The version without eu sounds very natural.

That a is the definite article the.

So:

• certidão de nascimento = birth certificate
• a certidão de nascimento = the birth certificate

Portuguese uses articles more often than English, especially with concrete nouns in normal statements.

Certidão de nascimento is the standard term for birth certificate.

Literally:

• certidão = certificate / official record
• de nascimento = of birth

This is a fixed expression in Portuguese, just like birth certificate is a fixed expression in English.

Portuguese often uses noun + de + noun where English uses a compound noun.

So instead of something like birth certificate as one compact unit, Portuguese says:

• certidão de nascimento = certificate of birth
• posto de atendimento = service post / service center
• carta de amor = love letter

This structure is very common and natural in Portuguese.

No is a contraction of:

• em = in / at
• o = the

So:

• em + o = no

That means:

• no posto de atendimento = at the service center

Other common contractions:

• na = em + a
• nos = em + os
• nas = em + as

Posto de atendimento is a place where people receive service, assistance, or administrative help.

Depending on context, it could be translated as:

• service center
• service desk
• customer service office
• assistance center

Literally:

• posto = post / station / service point
• atendimento = service / assistance / customer service

The exact English translation depends on the real-world setting.

In posto de atendimento, the phrase de atendimento functions almost like a label describing the kind of posto it is.

So Portuguese normally says:

• posto de atendimento
• not usually posto do atendimento

If you said do atendimento, it would usually sound more specific, like the service department’s post or the post related to a specific service. In most general cases, de atendimento is the normal form.

Not in this sentence.

The verb retirar can sometimes mean remove or take away, depending on context. But here, with a document and a service location, it means pick up or collect.

For example:

• Retiro o documento no balcão. = I pick up the document at the counter.
• Retiro a cadeira da sala. = I remove the chair from the room.

So context tells you which meaning is intended.

The given word order is very natural:

• Retiro a certidão de nascimento no posto de atendimento.

But Portuguese allows some flexibility. For example:

• No posto de atendimento, retiro a certidão de nascimento.

This version emphasizes the location a bit more.

Still, the original order is the most straightforward and neutral for a learner.

If you say:

• Vou retirar a certidão de nascimento no posto de atendimento.

it means I’m going to pick up the birth certificate at the service center.

This can sound more like a future plan or intention.

By contrast:

• Retiro a certidão de nascimento...

is simple present, which in Portuguese can describe a habitual action, a general statement, or sometimes even a scheduled/expected action depending on context.

A helpful approximation is:

• reh-TCHEE-roo in many Brazilian accents

A few notes:

• The r at the beginning of retiro is usually pronounced like a strong h sound in Brazilian Portuguese.
• The ti before a vowel often sounds like chee in many parts of Brazil.
• The final o is often pronounced like oo in normal speech.

So retiro may sound roughly like heh-CHEE-roo or reh-CHEE-roo, depending on the accent.

Yes, in some contexts pego could be understood as I get / I pick up the birth certificate.

However, retiro sounds more formal and is especially common in administrative, official, or service-related situations. Since this sentence is about a certificate and a service center, retiro is the more natural choice in a formal context.

So:

• retiro = more formal, common for documents/services
• pego = more everyday and informal