O fogo começou agora.

O is the masculine singular definite article, meaning the.

So o fogo = the fire.

Portuguese uses articles very often, and in this sentence it sounds natural to include it. It usually suggests a specific fire the speaker has in mind, not just fire in general.

Yes. Fogo is a masculine singular noun, so it takes o, not a:

• o fogo
• not a fogo

This is a grammatical gender point, not a statement about real-world gender.

Começou is the third-person singular preterite of the verb começar.

So it matches subjects like:

• ele começou
• ela começou
• você começou
• o fogo começou

In this sentence, the subject is o fogo, so começou means started / began.

Because the sentence talks about the start of the fire as a completed event.

The idea is: the fire’s beginning happened just now.

Portuguese commonly uses the preterite here, even where English might often say:

• The fire has just started

So começou agora is very natural in Portuguese.

If you used the present começa, it would usually suggest something like starts or is starting, which gives a different feel.

The ç is called cedilha.

It is used so that the c keeps an s sound before a, o, or u.

• começar → the ç sounds like s
• começou → still an s sound

Without the cedilla, comecou would suggest a k sound before o, which would be wrong.

So:

• ç before a/o/u = s sound

The acute accent in começou helps show stress and vowel quality.

The stressed syllable is the last one:

• co-me-ÇOU

A good learner takeaway is:

• stress falls on the final syllable
• the accent is not optional in correct spelling

So começou is correct, while comecou is not.

Yes, agora can move.

O fogo começou agora is a neutral, natural order.

You could also say:

• Agora o fogo começou
• O fogo agora começou

But those can sound more marked or emphatic depending on context.

For a simple statement, O fogo começou agora is a very normal word order.

In this sentence, it most naturally means just now or right now.

That is because it goes with a completed past form, começou.

So the feeling is not just a general now, but specifically:

• it started a moment ago
• it has just started

Yes, if the context already makes it clear what started.

Portuguese often leaves out information that is understood from the situation.

So if everyone is already talking about the fire, Começou agora can work as:

• It started just now

But if there is no clear context, O fogo começou agora is safer and clearer.

A simple approximate pronunciation is:

u FO-gu ko-me-SO a-GO-ra

A few helpful notes:

• o by itself is often pronounced like u when unstressed
• fogo is stressed on FO
• começou is stressed on the last syllable
• agora is stressed on GO

This is only an approximation for English speakers, but it is a useful starting point.

Sometimes, yes, but they are not always exactly the same.

• fogo = fire, a general everyday word
• incêndio = fire/blaze, often more specific, formal, or referring to an accidental/destructive fire

So:

• O fogo começou agora sounds natural in everyday language
• O incêndio começou agora is possible, but it sounds a bit more specific or formal

In many real situations, incêndio would be used when talking about a serious fire, especially in news or official language.