Explique o propósito agora.

Explique is the imperative form used to give a command or instruction to você in Brazilian Portuguese.

• explicar = the infinitive, to explain
• explica = can be the present tense he/she explains or an informal command to tu
• explique = a command to você, and also the same form as the present subjunctive

So in Explique o propósito agora, the speaker is telling someone: Explain the purpose now.

In Brazil, commands to você are extremely common, so explique sounds natural in many situations.

Yes, it is usually associated with the você form, which can sound:

• neutral
• polite
• sometimes formal, depending on context

In Brazilian Portuguese, você is very common in everyday speech, so explique does not automatically sound overly formal. It can simply be a normal instruction.

If you were speaking to someone with tu, the command would often be explica in many varieties:

• Explica o propósito agora.

But in much of Brazil, você forms are more common than tu forms.

O is the definite article the.

So:

• o propósito = the purpose

Portuguese uses definite articles more often than English does. In this sentence, the speaker is referring to a specific purpose, so o propósito is natural.

Without the article, Explique propósito agora, the sentence would sound unnatural in standard Portuguese.

The accent mark shows where the stress goes.

Propósito is stressed on the second syllable:

• pro-PÓ-si-to

Without the accent, Portuguese spelling rules would suggest a different stress pattern, so the accent is necessary.

It also helps distinguish the correct written form of the word.

Agora means now, and placing it at the end is very natural in Portuguese.

• Explique o propósito agora. = natural
• Agora, explique o propósito. = also natural, with more emphasis on now

So the position of agora can change depending on what the speaker wants to emphasize.

At the end, it often sounds like a straightforward instruction:

• Explain the purpose now.

At the beginning, it can sound more contrastive:

• Now explain the purpose.

Yes, you can. That word order is grammatically possible.

Compare:

• Explique o propósito agora.
• Explique agora o propósito.

Both are understandable, but the first one often sounds more neutral and natural in many contexts.

Putting agora before o propósito can give a little more emphasis to the timing:

• Explain now the purpose

So this is mainly a matter of word order and emphasis, not basic meaning.

Grammatically, it is a command in the imperative.

However, in real life, tone and context matter a lot. The same sentence can sound like:

• a firm command
• an instruction
• a prompt in a classroom or meeting
• a polite request, if said gently

Portuguese imperatives are often used in situations where English might also use softer wording like Please explain the purpose now. If you want to make it explicitly more polite, you could add por favor:

• Explique o propósito agora, por favor.

A rough guide for an English speaker is:

• explique ≈ ex-PLEE-kee
• o ≈ oo or a short oh, depending on speech
• propósito ≈ pro-POH-zee-too
• agora ≈ a-GOH-ra

A few useful pronunciation notes:

• In Brazil, unstressed e at the end of a word often sounds like ee, so explique ends roughly like kee.
• The s in propósito sounds like z here because it is between vowels.
• The r in agora is usually softer than English word-initial r.

A natural connected pronunciation may sound something like:

• es-PLEE-kee u pro-POH-zee-tu a-GOH-ra

Yes. Portuguese often leaves the subject pronoun out when it is understood from the verb form or from context.

In this sentence, the subject is an implied you:

• (Você) explique o propósito agora.

Portuguese does not need to say você here, because the command form already makes the meaning clear.

If you include the pronoun, it becomes:

• Você explique o propósito agora.

That version is usually less natural as a simple command, because Portuguese normally leaves the pronoun out in this kind of sentence.

Yes, in many contexts it could.

• propósito = purpose
• objetivo = objective, goal, aim

They are similar, but not always identical.

• propósito often refers to the reason or intended function behind something
• objetivo often refers more to a goal to be achieved

So:

• Explique o propósito agora. = Explain the purpose now.
• Explique o objetivo agora. = Explain the objective now.

Which one fits better depends on context.