O fumo denso assusta as crianças.

Breakdown of O fumo denso assusta as crianças.

a criança
the child
assustar
to scare
o fumo
the smoke
denso
dense
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Questions & Answers about O fumo denso assusta as crianças.

Why is it O fumo and not Um fumo?

O fumo uses the definite article o (the smoke), which suggests specific or known smoke (for example, the smoke we can see right now, or the smoke from that fire).

Um fumo would literally be a smoke, which is unusual in English and in Portuguese in this context. You’d normally use um fumo only in more special or idiomatic uses (e.g. dar um fumo – to take a drag, in some registers).

So for general or specific smoke as a substance that’s present, o fumo is the natural option.


Is fumo masculine or feminine, and how do I know?

Fumo is a masculine noun, so it takes o (singular) and os (plural):

  • o fumo – the smoke
  • os fumos – the smokes (rare; usually only in special contexts)

Many nouns ending in -o are masculine, which is a useful general rule, though there are exceptions. You mainly have to learn each noun’s gender, but the article in a dictionary (o fumo) will show you that it’s masculine.


Why is the adjective denso after the noun (fumo denso) instead of before it?

In Portuguese, the default position of descriptive adjectives is after the noun:

  • fumo denso – dense smoke
  • casa grande – big house
  • noite fria – cold night

Putting the adjective before the noun (denso fumo) is possible but less common and can sound more literary or emphatic, sometimes changing the nuance (for example, evoking a very vivid or poetic image).

In everyday, neutral Portuguese, noun + adjective (fumo denso) is the standard order.


What verb form is assusta, and what is the infinitive?

Assusta is:

  • the 3rd person singular,
  • present indicative of the verb assustar (to frighten, to scare).

Basic present indicative of assustar:

  • eu assusto – I scare
  • tu assustas – you scare (informal singular, mainly Portugal)
  • ele/ela/você assusta – he/she/you (formal) scare(s)
  • nós assustamos – we scare
  • eles/elas/vocês assustam – they/you (plural) scare

In O fumo denso assusta as crianças, o fumo denso is ele (3rd person singular), so the verb is assusta.


Why is it assusta and not assustam? Don’t we have a plural crianças?

The verb agrees with the subject, not with the object.

  • Subject: O fumo denso → singular
  • Verb: assusta → singular (matches o fumo)
  • Direct object: as crianças → plural (but objects don’t control the verb form)

If the subject were plural, you’d use assustam:

  • Os fumos densos assustam as crianças. – The dense smokes frighten the children.

Why do we say as crianças with the article? In English we just say “children”.

Portuguese uses definite articles more often than English, even when English has no article:

  • As crianças gostam de doces. – Children like sweets.
  • Os cães são animais fiéis. – Dogs are faithful animals.

Here, as crianças can mean:

  • the specific children we know, or
  • children as a known group in this situation.

You can say crianças without an article, but that often sounds more like a label or after certain verbs/prepositions (e.g. Ver crianças a brincar faz-me feliz – Seeing children play makes me happy). In this sentence, as crianças is the natural choice.


Why isn’t it às crianças with a preposition a?

Às = a (to) + as (the), so it usually marks an indirect object or direction:

  • O professor dá livros às crianças. – The teacher gives books to the children.

In O fumo denso assusta as crianças, as crianças is a direct object (the thing being frightened), not an indirect object. The verb assustar in this sense takes a direct object, so you just use the article:

  • assustar alguém – to scare someone

Hence: assusta as crianças, not assusta às crianças.


What’s the difference between fumo and fumaça?

In European Portuguese:

  • fumo is the normal, everyday word for smoke (e.g. from a fire, cigarette, chimney).
  • fumaça also exists but is much less common and can sound more literary, old-fashioned, or regional.

In Brazilian Portuguese:

  • fumaça is the usual everyday word for smoke.
  • fumo often refers more to tobacco, especially as a product (e.g. fumo de rolo, plantação de fumo).

Since you specified Portuguese from Portugal, O fumo denso assusta as crianças sounds perfectly normal and natural in European Portuguese.


If I used fumaça instead of fumo, what would change?

Fumaça is feminine, so everything that refers to it must agree:

  • A fumaça densa assusta as crianças. – The dense smoke frightens the children.

Changes:

  • article: o fumoa fumaça
  • adjective: denso (masc.) → densa (fem.), to agree with fumaça
  • verb stays assusta, because the subject is still singular (now a fumaça densa).

Why is the adjective denso masculine?

Adjectives in Portuguese agree in gender and number with the noun they modify:

  • o fumo denso – masculine singular
  • a fumaça densa – feminine singular
  • os fumos densos – masculine plural
  • as fumaças densas – feminine plural

Since fumo is masculine singular, the adjective takes the masculine singular form denso.


Can O fumo denso assusta as crianças also mean “The dense smoke is frightening the children right now”?

Yes. Portuguese simple present (assusta) can cover both:

  • a general fact: Dense smoke frightens children.
  • an action happening now: The dense smoke is frightening the children (right now).

If you want to be very explicit about an action in progress, you can use:

  • O fumo denso está a assustar as crianças. (Portugal)
  • O fumo denso está assustando as crianças. (Brazil)

But in many contexts, assusta alone is enough and natural.


How do I make this sentence negative or turn it into a question?

Negative:
Put não before the verb:

  • O fumo denso não assusta as crianças. – The dense smoke does not frighten the children.

Question (yes–no):
Usually, just use question intonation or a question mark; the word order stays the same:

  • O fumo denso assusta as crianças? – Does the dense smoke frighten the children?

In speech, your voice rising at the end signals it’s a question.


How would I say “It scares them” referring to the smoke and the children, using object pronouns?

You can replace as crianças with the object pronoun as (feminine plural) and attach it to the verb:

  • O fumo denso assusta-as. – The dense smoke scares them.

In European Portuguese written standard, pronouns usually attach to the verb (especially in affirmative statements). In spoken language you’ll also hear:

  • O fumo denso assusta-as. (attaching, standard)
  • In some informal speech, variants like O fumo denso assusta elas may occur, but assusta-as is the grammatically correct form.