O médico quer prevenir o contágio na sala.

The doctor wants to prevent contagion in the room.

Breakdown of O médico quer prevenir o contágio na sala.

• querer: to want
• em: in
• a sala: the room
• o médico: the doctor
• o contágio: the contagion
• prevenir: to prevent

Questions & Answers about O médico quer prevenir o contágio na sala.

In this sentence, does O médico mean a specific doctor, or “doctors” in general?

O médico here most naturally refers to one specific doctor that both speaker and listener know about from context.

• o = the (masculine singular definite article)
• médico = doctor (male doctor, or the profession in a neutral way)

In Portuguese you can use o médico generically (to talk about doctors as a group), for example:

• O médico tem de ser paciente.
  Literally: The doctor has to be patient.
  Meaning: A doctor / Doctors have to be patient.

But in your sentence, because it is so concrete (wants to prevent contagion in the room), it sounds like a specific doctor in a specific situation.

If you wanted to clearly talk about doctors in general in this sentence, you would more naturally say:

• Os médicos querem prevenir o contágio na sala.
  Doctors want to prevent contagion in the room.

Could I say Um médico quer prevenir o contágio na sala instead of O médico…? What is the difference?

Yes, you can say both, but they mean slightly different things.

• O médico quer prevenir o contágio na sala.
  → the doctor (a specific one) wants to prevent contagion in the room.

• Um médico quer prevenir o contágio na sala.
  → a doctor (one, but not identified / not important which one) wants to prevent contagion in the room.

So:

• o médico = the doctor we have in mind (maybe the one on duty, the one we both know).
• um médico = some doctor, one doctor; we’re introducing him for the first time or his precise identity doesn’t matter.

Grammatically both are fine; it’s just a question of specificity and context.

Why do we say prevenir o contágio and not just prevenir contágio without the article?

In Portuguese, it is very common to use a definite article with an abstract or general noun where English would omit it.

Compare:

• prevenir o contágio
• prevenir a gripe (prevent the flu)
• combater a fome (fight hunger)
• reduzir a poluição (reduce pollution)

In English we usually drop the article with general concepts (prevent contagion, fight hunger), but in Portuguese the default is to keep the article:

• o contágio = contagion / the contagion (as a concept)
• a fome = hunger / the hunger

You can sometimes drop the article in headlines or very telegraphic style (Prevenir contágio é importante), but in normal sentences, prevenir o contágio is the natural, standard form.

What exactly is the structure quer prevenir? Why is prevenir in the infinitive?

quer prevenir = wants to prevent.

• quer = 3rd person singular of querer (to want)
• prevenir = infinitive (to prevent)

In Portuguese, querer is followed directly by an infinitive, similar to English want to + verb:

• Ele quer comer. – He wants to eat.
• Ela quer sair. – She wants to go out.
• O médico quer prevenir o contágio. – The doctor wants to prevent contagion.

You do not conjugate the second verb:

• ✅ O médico quer prevenir o contágio.
• ❌ O médico quer previne o contágio.

So the pattern is:

querer + infinitive = to want to + verb

Is querer working like a modal verb here, like English “want to”?

Functionally, yes, it behaves somewhat like English want to:

• It expresses desire / intention.
• It is followed by an infinitive, which carries the main lexical meaning.

Examples:

• Quero aprender português. – I want to learn Portuguese.
• Eles querem viajar em agosto. – They want to travel in August.
• O médico quer prevenir o contágio. – The doctor wants to prevent contagion.

Unlike true modals (like can, must), querer is a fully conjugated lexical verb (quero, queres, quer, queremos, querem), but in this construction, it does a very similar job to English want to.

Could we use other verbs like evitar or impedir instead of prevenir? Do they mean the same thing?

They are related but not identical:

• prevenir = to prevent in advance, to take precautions so something does not start
• evitar = to avoid, to stay away from something or stop it from happening (often more general)
• impedir = to stop / block something, often once it is already starting or concrete

In your sentence, all are possible, but the nuance changes slightly:

• O médico quer prevenir o contágio na sala.
  → The doctor wants to put measures in place before there is contagion. (anticipation / prevention)

• O médico quer evitar o contágio na sala.
  → Very similar, but slightly more general: he wants to avoid contagion; not necessarily focusing on planning ahead.

• O médico quer impedir o contágio na sala.
  → Stronger, more like block / stop contagion; sounds a bit more forceful.

All are grammatically correct, but prevenir o contágio is very common in medical / public health contexts.

What exactly is na in na sala? Why not just em a sala?

na is a contraction:

• na = em + a (in + the, feminine singular)

So:

• em = in
• a = the (feminine singular)
• sala = room (feminine noun)

em a sala is not used; it always contracts:

• ✅ na sala – in the room
• ❌ em a sala

Similarly:

• no = em + o → no quarto (in the bedroom)
• nas = em + as → nas salas (in the rooms)
• nos = em + os → nos hospitais (in the hospitals)

In normal speech and writing, you must use the contractions.

What does sala mean here? Could it mean “living room” as well?

sala is a general word meaning room, but in many contexts it specifically suggests:

• sala = room, often a larger or main room (e.g. living room, classroom, waiting room, hall)

Depending on context, sala could be:

• sala (short for sala de estar) – living room
• sala de espera – waiting room
• sala de operações – operating theatre
• sala de aula – classroom

In your sentence, na sala just means in the room, and context (e.g. hospital, clinic, house) would tell you what type of room it is. If someone wanted to be specific (e.g. waiting room), they would usually say:

• O médico quer prevenir o contágio na sala de espera.

Why is it o contágio (masculine) and na sala (feminine)? How do we know the genders?

In Portuguese, every noun has grammatical gender, and the article must agree with it:

• o contágio

  • contágio is a masculine noun
  • so we use o (the, masculine singular)

• na sala

  • sala is a feminine noun
  • na = em + a (in + the, feminine singular)

Unfortunately, gender is mostly arbitrary, and you have to learn it with each noun. A few helpful patterns:

• Nouns ending in -o are often masculine:
  o médico, o livro, o contágio

• Nouns ending in -a are often feminine:
  a sala, a janela, a mesa

But there are exceptions, so when you learn a new noun, it’s best to learn it with its article:

• o contágio (masculine)
• a sala (feminine)

How flexible is the word order? Could I say O médico quer prevenir na sala o contágio?

Word order in Portuguese is less flexible than in some other Romance languages, and the natural order here is:

O médico quer prevenir o contágio na sala.
[subject] [verb] [object] [location]

You can move adverbial phrases like na sala around, but it often sounds marked or unnatural:

• Na sala, o médico quer prevenir o contágio.
  → Acceptable, but now you are emphasising the location (“In the room, the doctor wants to…”).

• O médico quer, na sala, prevenir o contágio.
  → Very unnatural / literary; not something you’d say in normal speech.

Putting na sala between the verb and its direct object (prevenir na sala o contágio) is technically understandable but sounds clumsy and unnatural in everyday Portuguese.

So for normal speech and writing, stay with:

• O médico quer prevenir o contágio na sala.

Could we express this idea with a clause, like O médico quer que não haja contágio na sala? How does that differ?

Yes, that is another natural way to express a similar idea:

• O médico quer prevenir o contágio na sala.
  → Focus on the action of preventing; he wants to take measures.

• O médico quer que não haja contágio na sala.
  → Literally: The doctor wants that there not be contagion in the room.
  → Focus on the desired state: he wants the room to be free of contagion.

Grammatically, the second uses:

• quer que
  • subjunctive
    
    • haja = present subjunctive of haver

This structure is very common when what you want is a situation / state rather than directly an action with an infinitive:

• Quero que venhas. – I want you to come.
• Ele quer que tudo corra bem. – He wants everything to go well.

In your original sentence, prevenir o contágio emphasizes the preventive action itself.

Could we say O médico quer prevenir que haja contágio na sala?

This is possible, but it is less natural in this specific context than your original sentence.

Patterns with prevenir que + subjunctive do exist, especially with more complex clauses:

• Queremos prevenir que o mesmo volte a acontecer.
  → We want to prevent the same thing from happening again.

• As vacinas ajudam a prevenir que as pessoas fiquem doentes.
  → Vaccines help prevent people from getting ill.

In your example, because contágio is a simple, concrete noun, the most idiomatic form is still:

• O médico quer prevenir o contágio na sala.

If you use a clause, most speakers would prefer:

• O médico quer que não haja contágio na sala.

How is this sentence pronounced in European Portuguese?

In European Portuguese, approximately (semi‑phonetic, not strict IPA):

• O médico quer prevenir o contágio na sala.
  /u MÉ-dee-ku kɛr prə-vee-NEER u kõ-TÁ-žiu nə SÁ-lə/

Key points:

• O at the beginning is often a short /u/, almost like “oo” in book.
• médico: stress on mé, final -ico is reduced: MÉ-də-ku.
• quer: like “care” but with a slightly more open e.
• prevenir: pre- is very reduced, almost prə-; stress on -nir.
• contágio: stress on tá, -gio sounds like žiu (like French j + “you”).
• na: clear nasal vowel.
• sala: SA-lə, with the final a reduced.

In European Portuguese, many unstressed vowels (especially final -o, -a, -e) are reduced to a schwa-like sound /ə/ or very weak vowel.

Is this sentence the same in Brazilian Portuguese, or would Brazilians say it differently?

The sentence is perfectly correct as-is in both European and Brazilian Portuguese:

• O médico quer prevenir o contágio na sala.

The main differences are in pronunciation, not grammar or vocabulary.

In Brazilian Portuguese (general educated pronunciation), roughly:

• O médico quer prevenir o contágio na sala.
  /u MÉ-dʒi-ku kɛʁ pɾe-ve-NEER u kõ-TÁ-dʒiu na SA-la/

Main contrasts with European Portuguese:

• Vowels are less reduced; they sound more like what is written.
• d before i often sounds like “dʒ” (like j in jeans): médico ≈ MÉ-dji-ku.
• Final vowels (-o, -a) are more clearly pronounced: médico, sala.
• r in quer, prevenir is usually a guttural sound /ʁ/ in many accents.

Grammatically and lexically, though, the sentence is natural in both varieties.