Learn Hardcore Portuguese (Portugal): O professor não quer mencionar o resultado agora. - The teacher does not want to mention the result now.

O professor = the teacher (a specific teacher the speakers have in mind).
Without the article (Professor) you’d normally be addressing the teacher directly, like a title:
- Professor, posso fazer uma pergunta? = Professor, may I ask a question?

So in your sentence, O professor refers to a particular teacher (for example, the one of this class), which is why the article O is used.

How do I say “female teacher” here? Is professor always masculine?

No. Professor is masculine; the feminine form is professora.

O professor = the (male) teacher
A professora = the (female) teacher

The article must agree in gender and number with the noun:

O professor não quer mencionar o resultado agora.
A professora não quer mencionar o resultado agora.
Os professores não querem mencionar o resultado agora. (plural, masculine or mixed)
As professoras não querem mencionar o resultado agora. (plural, all female)

Why is não placed before quer and not somewhere else?

In Portuguese, basic negation is formed with não directly before the conjugated verb.

O professor não quer mencionar… = The teacher does not want to mention…

In verb chains (more than one verb together), não goes before the first conjugated verb:

O professor não quer mencionar o resultado.
O professor não pode mencionar o resultado.
O professor não vai mencionar o resultado.

You normally cannot say “quer não mencionar” to mean simple negation; that sounds awkward or changes the meaning (it could sound like “he wants to not mention” with a special emphasis).

What is quer exactly? What verb is it from, and which form is it?

Quer is the 3rd‑person singular present tense of the verb querer (to want).

Partial present‑tense conjugation of querer:

eu quero – I want
tu queres – you want (informal singular)
ele / ela / você quer – he / she / you (formal) want
nós queremos – we want
vocês querem – you (plural) want
eles / elas querem – they want

So O professor quer… literally means The teacher wants…
With não: O professor não quer… = The teacher does not want…

Why is it quer mencionar and not something like “quer menciona”?

When you have two verbs together, the first verb is conjugated and the second stays in the infinitive.

Pattern: [conjugated verb] + [infinitive]

quer mencionar – wants to mention
quer comer – wants to eat
pode sair – can leave
vai falar – is going to speak

So:

O professor quer mencionar o resultado. – correct
O professor quer menciona o resultado. – incorrect

Could I use a different verb instead of mencionar? Is it formal?

Mencionar is quite neutral and a bit on the formal/standard side, similar to “to mention” in English. Common alternatives:

falar de – to talk about
- O professor não quer falar do resultado agora.
dizer – to say
- O professor não quer dizer o resultado agora.
revelar – to reveal
- O professor não quer revelar o resultado agora.

All of these are acceptable; they have slightly different nuances:

mencionar – simply bring it up / state it
falar de – talk about it, possibly at more length
revelar – reveal something that was hidden or unknown

Why is it o resultado and not um resultado?

O resultado = the result (specific, known to both speaker and listener).
Um resultado = a result (non‑specific, one of several possible results).

In this sentence, we’re clearly talking about a particular result (for example, the result of a test, exam, match, vote, etc.). That’s why the definite article o is used:

O professor não quer mencionar o resultado agora.
= The teacher doesn’t want to mention the (known, specific) result now.

If you said um resultado, it would sound like some result or other, not a clearly identified one.

Where can agora go in the sentence? Is it fixed at the end?

Agora (= now) is usually placed at the end here, but it can move a bit depending on emphasis. All of these are possible:

O professor não quer mencionar o resultado agora. (most natural)
Agora o professor não quer mencionar o resultado. (emphasises now as the time frame)
O professor agora não quer mencionar o resultado. (emphasises that at this moment he doesn’t want to)

The version in your sentence – …o resultado agora – is the most neutral and common word order.

Can I drop O professor and just say Não quer mencionar o resultado agora?

Grammatically, yes: Portuguese can drop subjects when they are clear from context.

Não quer mencionar o resultado agora.
= [He/She/You] doesn’t want to mention the result now.

However, without a previous context, this is ambiguous: it could mean he, she, or you (formal). In isolation, O professor… is clearer because it identifies who doesn’t want to mention the result.

How would I replace o resultado with a pronoun in European Portuguese?

There are two common ways in European Portuguese, both using the direct object pronoun o:

Before the conjugated verb (proclisis):
- O professor não o quer mencionar agora.
  = The teacher doesn’t want to mention it now.
Attached to the infinitive (enclisis) with a hyphen:
- O professor não quer mencioná‑lo agora.

Both are correct. In European Portuguese, Não o quer mencionar feels slightly more natural in everyday speech, but you’ll hear and read both structures.

Is this sentence formal, informal, or neutral in tone?

It’s neutral.

Vocabulary like professor, mencionar, resultado, agora is standard and not slangy.
The structure não quer + infinitive is common in both spoken and written Portuguese.

You can use this sentence in almost any context: talking to friends, describing a situation, or even in a formal setting.