Eu vou cortar a cebola agora.

Yes. In Brazilian Portuguese, eu can often be omitted because the verb form already shows the subject:

• (Eu) vou cortar a cebola agora.

Both versions are natural. Including eu can add clarity, emphasis, or contrast, especially if you want to stress I rather than someone else.

For example:

• Eu vou cortar a cebola agora, e você lava os pratos.

So eu is optional in many cases, but not wrong at all.

Vou cortar is the very common ir + infinitive structure in Portuguese.

• vou = I go / I am going
• cortar = to cut

Together, vou cortar means I am going to cut or very naturally I’ll cut.

This is one of the most common ways to talk about the near future in Brazilian Portuguese.

Other examples:

• Vou sair. = I’m going to leave.
• Vamos comer. = We’re going to eat.

You can say cortarei, but in everyday Brazilian Portuguese, vou cortar is much more common in normal conversation.

Compare:

• Vou cortar a cebola agora. = very natural, everyday speech
• Cortarei a cebola agora. = grammatical, but often sounds more formal, literary, or less conversational

So if you are learning spoken Brazilian Portuguese, vou cortar is the form you will hear much more often.

Here, a is the feminine singular definite article, meaning the.

• a cebola = the onion

Portuguese uses definite articles more often than English does. In this sentence, a cebola sounds very natural because you are talking about a specific onion, probably one already present in the situation.

If you wanted an onion, you would say:

• uma cebola

So:

• cortar a cebola = cut the onion
• cortar uma cebola = cut an onion

Because of its function in the sentence.

In Eu vou cortar a cebola agora, a comes directly before the noun cebola, so it is the article the.

• a cebola = the onion

Portuguese a can also be a preposition meaning to, but not in this sentence.

For example:

• Vou à cozinha. = I’m going to the kitchen.

There, a is part of the preposition/article combination. But in a cebola, it is just the article.

Cortar is a broad verb meaning to cut, and depending on context it can correspond to cut, slice, or sometimes chop in English.

In a kitchen context:

• cortar a cebola can naturally be understood as cut the onion
• Depending on the situation, an English speaker might also translate it as chop the onion or slice the onion

If you want to be more specific in Portuguese, other verbs may appear, such as:

• picar = to chop/mince
• fatiar = to slice

But cortar is a very normal general verb here.

Yes, agora is flexible.

These are all possible:

• Eu vou cortar a cebola agora.
• Agora eu vou cortar a cebola.
• Eu agora vou cortar a cebola.

The most natural choices are usually:

• Eu vou cortar a cebola agora.
• Agora eu vou cortar a cebola.

Putting agora at the end is very common and sounds completely natural. Putting it at the beginning often gives it a little more emphasis, like Now I’m going to cut the onion.

Usually yes, but like now in English, it can mean slightly different things depending on context.

It can mean:

• now / right now = at this moment
• now = at this point in the sequence of events

In Eu vou cortar a cebola agora, it most likely means now / right now.

If you want to make right now extra explicit, Brazilians may also say:

• agora mesmo
• neste momento

But plain agora is very common and natural.

In Brazilian Portuguese, cebola is commonly pronounced roughly like:

• seh-BOH-lah

A few helpful notes:

• ce sounds like seh
• stress is on bo
• final a is an unstressed ah

A rough pronunciation of the whole sentence would be:

• eh-ooh VOH kohr-TAHR ah seh-BOH-lah ah-GOH-rah

That is only an approximation for English speakers, but it can help at first.

Only vou changes, because it agrees with the subject. The infinitive cortar stays the same.

• Eu vou cortar a cebola agora. = I am going to cut the onion now.
• Você vai cortar a cebola agora. = You are going to cut the onion now.
• Ele vai cortar a cebola agora. = He is going to cut the onion now.
• Ela vai cortar a cebola agora. = She is going to cut the onion now.
• Nós vamos cortar a cebola agora. = We are going to cut the onion now.
• Eles vão cortar a cebola agora. = They are going to cut the onion now.

So this pattern is:

• ir conjugated + infinitive

It sounds natural. A Brazilian Portuguese speaker could absolutely say this in a real kitchen situation.

It is simple, everyday language:

• Eu vou cortar a cebola agora.

In casual speech, a Brazilian might also omit eu:

• Vou cortar a cebola agora.

That version is probably even more common in conversation, but both are natural.

Yes. In many contexts, English can translate vou cortar as either:

• I’m going to cut the onion now
• I’ll cut the onion now

The Portuguese structure is still the same: ir + infinitive. The best English translation depends on the situation.

For example:

• if someone asks who will do it, I’ll cut the onion now may sound best
• if you are simply describing your next action, I’m going to cut the onion now may sound best

So the Portuguese sentence can match either one naturally.