Vou registrar o extravio do celular.

Vou is the 1st person singular of ir (to go). In Brazilian Portuguese, ir + infinitive is a very common way to talk about the near future, just like be going to + verb in English.

So:

• vou registrar = I am going to register / file / report
• literally: I go to register
• natural meaning: I’m going to report/file...

This is often more common in everyday speech than the simple future form registrarei.

Here, registrar means something like:

• to register
• to record
• to file
• to officially report

In this context, it sounds official or bureaucratic. It is the kind of verb you might use for making a formal report with the police, a phone company, or an institution.

So registrar o extravio is closer to:

• to officially report the loss
• to file a report about the missing phone

Extravio is a formal noun meaning:

• loss
• misplacement
• the fact that something went missing

It is more formal than the everyday idea of simply saying I lost my phone.

Common contrast:

• Perdi meu celular. = I lost my phone.
• Vou registrar o extravio do celular. = I’m going to officially report the loss/misplacement of the phone.

So extravio is often used in administrative, legal, or service-related situations.

Because the sentence is more formal and focuses on the official act of reporting the event, not just describing what happened.

Compare:

• Perdi o celular. = I lost the phone.
• Vou registrar o extravio do celular. = I’m going to file an official report of the phone’s loss.

Using the noun extravio gives the sentence a more institutional tone, like something you might say at a police station, service desk, or insurance office.

Do = de + o = of the

So:

• o extravio do celular
• literally: the loss of the phone

Portuguese often uses this kind of structure where English might also use possession:

• the phone’s loss is not natural English
• so English says the loss of the phone
• Portuguese says o extravio do celular

The do shows that the loss refers to the phone.

Because extravio is a masculine singular noun here, so it takes the definite article o:

• o extravio = the loss

Portuguese uses articles more often than English does. In many formal expressions, the article sounds very natural and expected.

So registrar extravio do celular would sound incomplete or unnatural in standard Portuguese.
Registrar o extravio do celular is the normal phrasing.

Yes, absolutely.

• Vou registrar o extravio do meu celular. = I’m going to report the loss of my cellphone.

The original sentence uses do celular, which can sound a little more neutral or generic, depending on context. But in real life, if you mean your own phone, do meu celular is often clearer.

You may also hear:

• Vou registrar a perda do meu celular.
• Vou fazer um boletim de ocorrência pelo extravio do meu celular.

Yes. Celular is masculine in Portuguese:

• o celular
• meu celular
• um celular novo

So adjectives and articles used with it should normally be masculine too.

It is understandable and correct, but it sounds somewhat formal and bureaucratic.

In everyday speech, Brazilians might more often say things like:

• Perdi meu celular.
• Vou informar que perdi meu celular.
• Vou fazer um boletim de ocorrência.
• Vou registrar a perda do celular.

So the original sentence is natural in a formal context, but not the most casual everyday wording.

These words are related but not the same:

• extravio = loss / misplacement / disappearance
  Often formal; may suggest you do not know exactly where it went.
• perda = loss
  More general and common.
• roubo = robbery / theft involving force or threat
• furto = theft without direct confrontation

So if the phone was stolen, you would not normally say extravio unless you are being vague or uncertain.

Examples:

• Perdi meu celular. = I lost my phone.
• Houve extravio do celular. = The phone went missing / there was a loss of the phone.
• Roubaram meu celular. = They stole my phone.
• Foi furto. = It was theft.

Yes. You could say:

• Registrarei o extravio do celular.

This is grammatically correct, but it sounds more formal, written, or deliberate. In spoken Brazilian Portuguese, vou registrar is much more common.

So:

• vou registrar = natural in speech
• registrarei = more formal, often less common in casual conversation

A careful approximate pronunciation is:

• Vou ≈ voh or voo
• registrar ≈ heh-jis-TRAR or reh-jis-TRAR, depending on accent
• o ≈ oo
• extravio ≈ es-trah-VEE-oo
• do ≈ doo
• celular ≈ seh-loo-LAR

A rough full approximation:

voh heh-jis-TRAR oo es-trah-VEE-oo doo seh-loo-LAR

A few notes for Brazilian Portuguese:

• The r at the beginning of a word or syllable is often pronounced like an English h sound in many accents.
• The final stressed syllable in celular is -lar.
• extravio has stress on vi: ex-tra-vi-o.

Yes. Registrar is very common in formal and administrative language. For example:

• registrar uma ocorrência = to file an incident report
• registrar uma reclamação = to file a complaint
• registrar um boletim de ocorrência = to file a police report
• registrar o nascimento = to register a birth

So in your sentence, registrar o extravio fits that same official pattern.