Learn Hardcore Portuguese (Portugal): O gato parece chateado porque ninguém brinca com ele hoje. - The cat seems annoyed because nobody is playing with him today.

O gato parece chateado = The cat seems/looks upset.
You’re describing your impression from the outside (maybe from its face or behavior).
O gato está chateado = The cat is upset.
You’re stating it as a fact, as if you know for sure the cat is upset.

So parece chateado keeps a bit of subjectivity / uncertainty: it looks that way to you, but you’re not completely sure.

Could I also say O gato parece estar chateado? Is it different?

Yes, you can say:

O gato parece estar chateado.

It means essentially the same as O gato parece chateado.

Differences:

O gato parece chateado – shorter, more natural in everyday speech.
O gato parece estar chateado – a bit more explicit and slightly more formal or careful in style. You’re literally saying seems to be upset instead of seems upset.

Both are correct in European Portuguese.

Why is it chateado and not chateada or something else?

Chateado is an adjective and must agree in gender and number with the noun it describes.

o gato (masculine, singular) → chateado
a gata (feminine, singular) → chateada
os gatos (masculine, plural) → chateados
as gatas (feminine, plural) → chateadas

In your sentence, o gato is masculine singular, so the correct form is chateado.

What exactly does chateado mean in European Portuguese? Is it more like “annoyed” or “bored”?

In European Portuguese, chateado most often means:

annoyed / irritated
upset / a bit unhappy

It can sometimes overlap with bored, but bored is more naturally:

aborrecido (in Portugal)
entediado / aborrecido (in Brazil)

So in Portugal, um gato chateado is usually understood as an annoyed or upset cat, not mainly a bored one.

How does ninguém work here? Why don’t we also use não?

Ninguém means nobody / no one and is already negative.

In European Portuguese:

When a negative word like ninguém, nunca, nada comes before the verb, you do not add não:
- Ninguém brinca com ele. = Nobody plays with him.
- Nunca vou lá. = I never go there.
If the negative word comes after the verb, then you use não before the verb:
- Não brinca ninguém com ele.
- Não vai lá nunca.

So ninguém brinca com ele is correct; ninguém não brinca com ele would be wrong in standard Portuguese.

Why is it ninguém brinca (singular) and not ninguém brincam (plural)?

Even though ninguém refers to more than one person in meaning (no people), grammatically it behaves as singular, like ele/ela.

So you conjugate the verb in the 3rd person singular:

Ninguém brinca com ele. ✅
Ninguém brincam com ele. ❌ (incorrect)

Other examples:

Ninguém sabe. = Nobody knows.
Ninguém veio. = Nobody came.

Why is it brinca com ele and not brinca ele?

Because in Portuguese the verb brincar (to play) in this sense is normally used with the preposition com when you say who/what you play with:

brincar com alguém = to play with someone
brincar com o gato = to play with the cat
brincar com ele = to play with him

So:

ninguém brinca com ele = nobody plays with him

Brincar ele would sound wrong; you need com here.

Could I say ninguém brinca com o gato instead of com ele?

Yes, absolutely:

ninguém brinca com o gato = nobody plays with the cat
ninguém brinca com ele = nobody plays with him

Differences:

com o gato names the animal directly.
com ele is a pronoun referring back to something already mentioned (here, o gato in the previous part of the sentence).

In your sentence, com ele is natural and avoids repeating o gato.

Why does the sentence use brinca (simple present) instead of está a brincar (present continuous)?

In European Portuguese, the simple present is very often used for present, ongoing actions or general situations, more than in English.

ninguém brinca com ele hoje can mean:
- nobody is playing with him today (today’s situation), or
- nobody plays with him today (more general reading).

If you say:

ninguém está a brincar com ele hoje

then you highlight more strongly an ongoing action right now (at this moment).

Both are correct; in everyday speech, ninguém brinca com ele hoje is very natural.

Why is hoje at the end? Can I move it to another position?

Yes, hoje (today) is an adverb and can move around quite freely. All of these are possible:

O gato parece chateado porque ninguém brinca com ele hoje.
O gato parece chateado porque hoje ninguém brinca com ele.
Hoje, o gato parece chateado porque ninguém brinca com ele.

Differences:

Hoje, o gato parece… – emphasizes today as the special context.
…porque hoje ninguém brinca… – focuses on today nobody plays with him.
…ninguém brinca com ele hoje – neutral, very common ordering.

What you can’t normally do is split the verb and the subject with hoje in an odd way, like:

❌ porque ninguém hoje brinca com ele (possible, but sounds more marked/poetic than everyday speech).

What is the difference between porque, por que, and porquê? Why is it porque here?

They look similar but are used differently:

porque – conjunction meaning because (or why in informal answers):
- Estou em casa porque estou doente.
- …porque ninguém brinca com ele hoje. ✅
por que – por + que, mainly used in questions (why / for what):
- Por que estás chateado? = Why are you upset?
porquê – noun meaning reason / the why:
- Não entendo o porquê. = I don’t understand the reason.

In your sentence we need because, so porque is the correct form.

If the subject was plural, how would the sentence change?

Let’s change o gato (singular) to os gatos (plural):

Os gatos parecem chateados porque ninguém brinca com eles hoje.

Changes:

parece → parecem (verb agrees with plural os gatos)
chateado → chateados (adjective agrees in number and gender)
ele → eles (pronoun referring to plural cats)

Ninguém brinca stays singular, because ninguém is always grammatically singular.

How do you pronounce tricky words like ninguém and brinca in European Portuguese?

Approximate IPA (European Portuguese):

O gato parece chateado porque ninguém brinca com ele hoje.
/u ˈɡatu pɐˈɾes(ə) ʃɐtiˈadu puɾˈke nĩˈɡẽj ˈbɾĩkɐ kõ ˈelɨ ˈoʒ(ɨ)/

Key points:

ninguém → /nĩˈɡẽj/
- nasal ni- (like French vin), ending like -gẽi in ganguei.
brinca → /ˈbɾĩkɐ/
- br- rolled or tapped r, nasal -in-.
Final -e in ele and porque is usually a very short, almost neutral vowel /ɨ/.
hoje → /ˈoʒ(ɨ)/, roughly like OH-zh(uh).