Learn Hardcore Portuguese (Brazil): Quando o céu está azul, eu gosto de caminhar na cidade. - When the sky is blue, I like to walk in the city.

estar is used for temporary states or conditions (how something is at this moment).
ser is used for permanent characteristics, identity, definitions.

“O céu está azul” = The sky is (currently) blue – it can change later (cloudy, gray, etc.), so it’s seen as a temporary state, so you use está.

If you said “O céu é azul”, it would sound like you’re describing an inherent fact about the sky (more like “the sky is blue (by nature)”), which is less natural in this context.

Why do we say “gosto DE caminhar” and not just “gosto caminhar”?

In Portuguese, the verb gostar (to like) is almost always followed by the preposition de:

gostar de + noun:
- Eu gosto de música. = I like music.
gostar de + infinitive (verb):
- Eu gosto de caminhar. = I like to walk.

So “gosto caminhar” is incorrect. You must say “gosto de caminhar”.

Why is it “na cidade” and not “em a cidade”?

Na is a contraction:

em + a = na (feminine singular)
em + o = no (masculine singular)

Since cidade is feminine (a cidade), we get:

em a cidade → na cidade

So “na cidade” literally means “in the city” (or “in the town”). Saying “em a cidade” is grammatically wrong in normal speech and writing; you need the contraction.

Could I also say “pela cidade” instead of “na cidade”? What’s the difference?

Yes, but the meaning changes slightly:

caminhar na cidade = walk in the city (location in general)
caminhar pela cidade = walk around/through the city (suggests movement across different parts/areas)

pela is a contraction of por + a and often has the idea of through, around, by, along.

Why is there a comma after “azul”? Do commas work like in English with “when”-clauses?

Yes, very similar:

When the “quando”-clause comes first, you usually put a comma:
- Quando o céu está azul, eu gosto de caminhar na cidade.
If you put the main clause first, the comma is usually omitted:
- Eu gosto de caminhar na cidade quando o céu está azul.

So the comma here follows normal Portuguese punctuation rules for dependent clauses, much like in English.

Can I drop “eu” and just say “Quando o céu está azul, gosto de caminhar na cidade”?

Yes, that’s perfectly correct:

Quando o céu está azul, gosto de caminhar na cidade.

Portuguese verb endings already show who the subject is (gosto = I like), so the subject pronoun eu is optional.

In Brazilian Portuguese, people often keep the pronoun (especially in speech) for clarity or emphasis, but dropping it is grammatically fine.

Why is the verb after “gosto de” in the infinitive form (caminhar) and not conjugated?

After gostar de, you use:

a noun:
- Eu gosto de chocolate.
or a verb in the infinitive:
- Eu gosto de caminhar.

The infinitive (caminhar) works like a noun phrase here (“walking / to walk”), so it stays in the base form — you don’t conjugate it (caminho, caminhas, caminhamos ...) after de.

What’s the difference between “caminhar” and “andar”?

Both can translate as “to walk”, but they’re not always interchangeable:

caminhar
- More specifically “to walk (for exercise, leisure, movement on foot)”.
- Sounds a bit more neutral or slightly more “formal”/careful:
  - Eu gosto de caminhar na cidade. = I like walking in the city.
andar
- Very general: “to walk”, but also “to go/ride” with some means of transport:
  - Eu ando muito a pé. = I walk a lot (go by foot).
  - Eu ando de bicicleta. = I ride a bike.

In this exact sentence, “Eu gosto de andar na cidade” would still be understood and acceptable, but “caminhar” fits very naturally for “go for walks”.

Why is it “o céu” and not just “céu”?

Portuguese uses the definite article (o, a, os, as) more frequently than English.

o céu = literally “the sky”

In English, you might say “When the sky is blue...” or just “When sky is blue...” (the second sounds wrong). In Portuguese, you almost always need the article here:

Quando o céu está azul... ✅
Quando céu está azul... ❌ (sounds wrong / incomplete)

What’s the difference between “Quando o céu está azul” and “Se o céu está azul”?

Quando = when / whenever (talks about a situation that does happen at times)
- Quando o céu está azul, eu gosto de caminhar...
  = Whenever the sky is blue, I like to walk...
Se = if (expresses a condition; it may or may not happen)
- Se o céu está azul, eu gosto de caminhar...
  = If the sky is blue, I like to walk...

In everyday speech, people could say “Se o céu estiver azul...” for a future possibility, but for a habitual situation, quando is the natural choice.

Can this sentence also refer to the future time, or is it only present?

Grammatically, it’s present tense, expressing a habitual action:

Quando o céu está azul, eu gosto de caminhar na cidade.
= Whenever the sky is blue (whenever that happens), I (tend to) like walking in the city.

In Portuguese, the simple present (está, gosto) is often used for general truths and habits, just like in English.

If you wanted to focus on a specific future moment, you might say:

Quando o céu estiver azul, eu vou caminhar na cidade.
= When the sky is blue (in the future), I will walk in the city.

What do the accents in “céu” and “está” do? Are they important?

Yes, they’re important:

céu (not ceu)
- The é with an acute accent shows stress on that syllable and an open “eh” sound.
- Pronunciation: roughly “seh-oo” in one quick syllable, similar to “seh” + a short “w” at the end.
está (not esta)
- está = is (verb estar, 3rd person singular, present)
- esta = this (feminine demonstrative: “this (one)”)

So the accent changes both pronunciation and meaning.
“O céu está azul” = The sky is blue.
“O céu esta azul” (without accents) would be considered misspelled and could be confusing.

Is the word order fixed? Can I move parts of the sentence around?

You have some flexibility. All of these are natural:

Quando o céu está azul, eu gosto de caminhar na cidade.
Eu gosto de caminhar na cidade quando o céu está azul.
Quando o céu está azul, gosto de caminhar na cidade. (dropping eu)

The meaning stays the same; only emphasis and rhythm change slightly. The most neutral options are the first two.