A equipe vai começar a missão.

Here, a means the.

That is because equipe is a feminine singular noun, so the definite article is a:

• a equipe = the team

Compare:

• a equipe = the team
• uma equipe = a team

So in this sentence, A equipe means The team, not A team.

In Portuguese, every noun has a grammatical gender, and equipe is feminine.

That affects the article used with it:

• a equipe = the team
• not o equipe

This is grammatical gender, not biological gender. Even if the team is made up of men, women, or both, the noun equipe is still feminine.

Vai começar is a very common way to express the near future in Brazilian Portuguese.

It is formed with:

• ir in the present tense + infinitive

So:

• vai começar = is going to start / will start

Comparison:

• começa = starts / is starting depending on context
• vai começar = is going to start
• começará = will start (simple future, often a bit more formal or written)

In everyday Brazilian Portuguese, vai começar is extremely common and natural.

Because the subject is a equipe, and grammatically that is singular.

Even though a team contains multiple people, the noun itself is singular:

• a equipe vai = the team is going to...

If the subject were plural, you would use vão:

• as equipes vão começar = the teams are going to start

This is similar to English when we treat the team as a single unit.

Yes. Equipe is a collective noun. It refers to a group of people, but grammatically it is usually treated as singular.

So you normally say:

• A equipe vai começar a missão.

Not:

• A equipe vão começar...

In Brazilian Portuguese, singular agreement is the standard choice with equipe.

Because começar can be used directly with a noun as a direct object:

• começar a missão = start the mission

So in this sentence:

• A equipe vai começar a missão.

the verb começar directly takes a missão.

You may see other patterns in other contexts, for example:

• começar com algo = start with something
• começar por algo = begin with something
• começar a fazer algo = begin to do something

But here the meaning is simply to start the mission, so no extra preposition is needed.

In a missão, the a is the definite article meaning the.

So the sentence has two different a words:

• A equipe → the team
• a missão → the mission

Neither one is part of the verb. They are both articles.

This can be confusing because Portuguese uses a both as:

• a feminine singular article: a missão
• a preposition in other situations

But in this sentence, both are articles.

Yes. That is correct.

• A equipe vai começar a missão. = very common, conversational
• A equipe começará a missão. = also correct, a bit more formal or literary

In everyday spoken Brazilian Portuguese, people often prefer vai começar over the simple future começará.

Both can mean to start or to begin.

So these are both possible:

• A equipe vai começar a missão.
• A equipe vai iniciar a missão.

In general:

• começar is extremely common and neutral
• iniciar can sound a little more formal, technical, or official in some contexts

For natural everyday speech, começar is often the safest choice.

Yes. Missão can be used in several ways, depending on context:

• a military mission
• a space mission
• a work assignment
• a religious mission
• a special objective or task

So a missão does not automatically have to be military. The exact meaning depends on the situation.

A helpful approximation is:

• equipe ≈ eh-KEE-pee

A few pronunciation notes:

• the stress is on qui: e-QUI-pe
• the qu here sounds like k
• the final e in Brazilian Portuguese is often pronounced like a short ee sound

So it sounds roughly like eh-KEE-pee.

A useful approximation is:

• missão ≈ mee-SOWN with a nasal ending

Important points:

• stress is on the last syllable: mis-SÃO
• ss sounds like English s in see
• ão is a very common Portuguese nasal ending, and English does not have an exact equivalent

A rough learner-friendly version is:

• mee-SOWN

But try to make the final sound nasal rather than a clear ow.

The normal and most natural order here is:

• A equipe vai começar a missão.

Portuguese does allow some word-order variation, but not all rearrangements sound natural.
Vai começar a missão a equipe sounds odd in most normal contexts.

If you want emphasis, you might hear things like:

• A missão, a equipe vai começar agora.

But for a basic statement, stick with:

• Subject + verb phrase + object
• A equipe vai começar a missão.

In standard Portuguese, that would usually sound incomplete or unnatural in a normal sentence.

The most natural version is:

• A equipe vai começar a missão.

Portuguese uses articles more often than English does. So where English might sometimes omit the, Portuguese often keeps it.

In headlines, notes, or very telegraphic styles, articles may be dropped, but for normal speech and writing, use them here.