Não só a sala, mas também o quarto precisam ser limpos hoje.

It means not only ... but also.

This structure connects two ideas and adds emphasis to the second one. In this sentence, the speaker is saying that the room is not the only thing that needs cleaning; the bedroom does too.

It is a very common pattern in Portuguese: Não só a sala, mas também o quarto... = Not only the living room, but also the bedroom...

You can use the same pattern with nouns, verbs, adjectives, or whole clauses.

Because together they form a compound subject.

Even though a sala is singular and o quarto is singular, the sentence is talking about both of them, so Portuguese uses a plural verb:

a sala + o quarto = precisam

This is the same idea as in English: The room and the bedroom need to be cleaned not needs

So precisam agrees with the full subject, not with each noun separately.

Because limpos agrees with both nouns together, and when Portuguese has a mixed-gender group, the default agreement is masculine plural.

Here you have:

• a sala = feminine singular
• o quarto = masculine singular

Together, they become a mixed group, so Portuguese uses:

• limpos = masculine plural

If both nouns were feminine, you would get limpas: A sala e a cozinha precisam ser limpas.

If both were masculine, you would also get limpos: O quarto e o escritório precisam ser limpos.

Because this is a passive structure.

precisam ser limpos means need to be cleaned.

The focus is on what needs to happen to the room and the bedroom, not on who will do the cleaning.

Compare:

• A sala e o quarto precisam ser limpos
  = The room and the bedroom need to be cleaned

• A sala e o quarto precisam estar limpos
  = The room and the bedroom need to be clean

Those are different ideas.
ser limpos focuses on the cleaning action.
estar limpos focuses on the resulting condition.

In this sentence, limpos is the normal and natural choice.

Portuguese often uses limpo, limpa, limpos, limpas in passive or adjective-like contexts:

• A casa foi limpa
• Os quartos foram limpos

The form limpado does exist, especially in some verbal contexts, but limpo sounds much more natural here.

So for a learner, the safest takeaway is:

• precisam ser limpos = natural
• precisam ser limpados = possible in some contexts, but not the best choice here

Because Portuguese uses definite articles much more often than English.

So where English might say: room or bedroom

Portuguese often says: a sala o quarto

In this sentence, the articles make the nouns sound specific and natural. They suggest that the speaker has particular rooms in mind, not just any room or bedroom.

Leaving the articles out here would sound unnatural in normal Portuguese.

Yes. Portuguese allows some flexibility with adverb placement.

The original sentence: Não só a sala, mas também o quarto precisam ser limpos hoje.

You could also say: Hoje, não só a sala, mas também o quarto precisam ser limpos.

Both are correct. The difference is mostly one of emphasis:

• ... hoje puts the time at the end in a very natural, neutral way
• Hoje, ... emphasizes today

The version with hoje at the end is very common and sounds quite natural.

Yes. Those are good alternatives.

All of these mean roughly the same thing:

• não só ... mas também
• não apenas ... mas também
• não somente ... mas também

In Brazilian Portuguese, não só ... mas também is very common and natural.

You may also hear slightly shorter variations, such as: Não só a sala, mas o quarto também...

That is also natural.

Yes, absolutely.

That version is simpler and more neutral: A sala e o quarto precisam ser limpos hoje.

The original sentence with não só ... mas também adds emphasis. It suggests something like: It is not only the room that needs cleaning; the bedroom does too.

So the difference is mainly in focus and emphasis, not basic meaning.

Yes, it is natural, but it sounds a little more formal or written because of the passive structure precisam ser limpos.

In everyday Brazilian Portuguese, people might also say:

Hoje, precisamos limpar não só a sala, mas também o quarto.

Or even:

Hoje tem que limpar não só a sala, mas também o quarto.

These versions are more conversational because they use an active structure instead of the passive.

So:

• precisam ser limpos = correct, natural, a bit more formal
• precisamos limpar or tem que limpar = very common in everyday speech

In this context, yes, quarto most naturally means bedroom.

The word quarto can mean different things depending on context, such as:

• bedroom
• quarter
• fourth

But in the sentence a sala ... o quarto, it is clearly being used as a noun for a part of a house, so bedroom is the natural reading.

That is why learners should read sala and quarto here as two rooms in a home.