Learn Hardcore Portuguese (Portugal): O gorro é azul e o cinto castanho combina com as botas. - The beanie is blue and the brown belt matches the boots.

Use ser to state inherent or characteristic properties, like a garment’s color. Estar would suggest a temporary or unusual state: O gorro está azul (it looks blue right now, maybe because of lighting). So é is the natural choice for color descriptions.

Why do we use the articles o and as here? Could I drop them?

Portuguese uses definite articles more than English when referring to specific items. O gorro, o cinto, and as botas point to particular objects the speaker has in mind. You can drop the article only if you mean things in general: combina com botas = it matches boots in general.

Do I need to repeat the article o before cinto? Could I say O gorro é azul e cinto castanho…?

Yes, repeat the article. In Portuguese you normally place the article with each new noun phrase: … e o cinto castanho…. Omitting it here sounds incorrect.

Why is castanho after cinto? Can it go before?

Adjectives typically follow the noun in Portuguese, especially colors: o cinto castanho. Placing it before (o castanho cinto) is unusual and can sound poetic or marked; with colors, post-nominal position is the norm.

Why is it combina com and not something like combina a or combina de?

With the sense of items matching or going well together, the verb is combinar com: o cinto combina com as botas. Natural alternatives include condiz com, vai bem com, and fica bem com.

Why is the verb combina singular when botas is plural?

The subject of the verb is o cinto (singular), so the verb is combina. As botas is the object of the preposition com. If both were subjects, you’d use plural: O cinto e as botas combinam.

Does castanho have to agree with gender and number? How would it change?

Yes. Castanho agrees with the noun:

Masculine singular: castanho (o cinto castanho)
Feminine singular: castanha (a bota castanha)
Masculine plural: castanhos (os cintos castanhos)
Feminine plural: castanhas (as botas castanhas)

Does azul change for gender/number?

It doesn’t change for gender, but it does for number:

Singular (masc. or fem.): azul (o gorro azul / a bota azul)
Plural: azuis (os gorros azuis / as botas azuis)

Could I also say O cinto é castanho e combina com as botas? How is that different from o cinto castanho combina…?

Both are correct. O cinto é castanho e combina… makes two statements about the belt (its color, and that it matches). O cinto castanho combina… uses an attributive adjective to identify which belt you’re talking about (the brown one) and then states that it matches.

What’s the difference between gorro, boné, and chapéu?

Gorro: a beanie/knit cap (no brim).
Boné: a cap with a visor (a baseball cap).
Chapéu: a hat with a brim (e.g., fedora, sun hat).
In Portugal, gorro specifically suggests a beanie.

Is castanho the usual word for “brown” in Portugal? What about marrom?

In European Portuguese, castanho is the standard for the color brown (clothes, hair, eyes). Marrom is common in Brazil; in Portugal it’s understood but not the default.

Could I leave out as and say combina com botas?

Yes, if you mean boots in general. Using as botas points to specific boots the listener can identify (the ones being worn, or previously mentioned).

Why isn’t there a comma before e?

In Portuguese, you generally don’t put a comma before e when it simply links two clauses or phrases: O gorro é azul e o cinto…. A comma could appear with longer, more complex structures or for parenthetical pauses, but not in this straightforward coordination.

Any quick pronunciation tips for key words here (European Portuguese)?

e (the conjunction) sounds like English “ee.”
é is open “eh.”
gorro: strong guttural rr; final o is like “oo”: roughly GO-rr-oo.
cinto: the in is nasalized: roughly SEEN-too.
botas: roughly BOH-tash; the final s sounds like “sh” in European Portuguese.
combina: stress on BI: kohm-BEE-nuh; com has a nasal vowel.

Could I say As botas combinam com o cinto castanho instead?

Yes. That flips the focus so the boots are the subject. The meaning is the same: the items match; only the emphasis changes.

Are there synonyms for the whole phrase “matches the boots” besides combina com as botas?

Yes:

condiz com as botas
vai bem com as botas
fica bem com as botas All are natural in European Portuguese; combina com is the most common and neutral.