Gosto de fones sem fios porque posso caminhar no parque enquanto ouço um podcast.

In Portuguese, the verb gostar almost always needs the preposition de after it.

• gostar de + noun = to like (something)
  
  • Gosto de fones. = I like headphones.

You cannot say gosto fones – that’s ungrammatical because gostar needs de.

About de vs dos:

• Gosto de fones sem fios.
  = I like wireless headphones (in general, as a category).
• Gosto dos fones sem fios.
  = I like the wireless headphones (some specific ones we both know about).

So:

• gostar de + noun (without article) → liking something in general
• gostar de + article + noun → liking some specific, known thing(s)

In Portugal:

• auscultadores – the more standard/neutral word for headphones (often used in writing, shops, more formal speech).
• fones – shorter, more colloquial/informal; very common in everyday conversation, especially with younger speakers.

They usually mean the same thing in Europe:

• fones (de ouvido) ≈ auscultadores

In Brazil, fone de ouvido is the usual term; in Portugal, auscultadores or just fones is more natural.

Your sentence is perfectly natural in European Portuguese: Gosto de fones sem fios...

Literally:

• fio = wire
• sem fio(s) = without wire(s)

The fixed expression for wireless in European Portuguese is:

• sem fios (plural) = “wireless”

Examples:

• fones sem fios = wireless headphones
• rato sem fios = wireless mouse
• internet sem fios = wireless internet / Wi‑Fi

You can say sem fio in some literal, physical contexts (without a wire / without one cable), but for the tech meaning “wireless”, people almost always use the plural sem fios.

In your sentence, porque means because:

• Gosto de fones sem fios porque posso caminhar...
  = I like wireless headphones because I can walk...

Portuguese has several similar-looking forms:

1. porque – because (conjunction)

   • Não fui porque estava doente. = I didn’t go because I was ill.

2. por que – why (in questions) or for which/that (in some relative clauses)

   • Por que chegaste tarde? = Why did you arrive late?

3. porquê (noun) – the reason / the why

   • Ninguém sabe o porquê. = Nobody knows the reason.

4. por quê – why? only when it comes at the end of a sentence (Brazilian usage; in European Portuguese you’ll usually just see porquê? or por que?)

In your sentence, we’re giving a reason, so we need porque = because.

Both are possible, but there’s a nuance:

• caminhar = to walk (specifically moving on foot, often with the idea of walking for exercise, strolling, etc.)
• andar = very broad: to walk, to go around, to move about, to ride, to go (depending on the context)

In your sentence:

• posso caminhar no parque emphasizes walking in the park.
• posso andar no parque is also correct, and in everyday speech in Portugal, andar is extremely common for plain “walk”.

So:

• More specific/neutral here: caminhar no parque
• Very natural, everyday: andar no parque

Both work in European Portuguese.

no is a contraction of the preposition em (in/on/at) + the masculine singular article o (the):

• em + o = no

So:

• no parque = in the park / at the park

Similarly:

• na = em + a (feminine singular) → na praia = in the beach/at the beach
• nos = em + os (masculine plural) → nos parques = in the parks
• nas = em + as (feminine plural) → nas cidades = in the cities

You normally must use the contracted form in speech and writing:

• ✔ no parque
• ✖ em o parque (not used)

Portuguese is a “pro‑drop” language: subject pronouns (eu, tu, ele, etc.) are often omitted because the verb ending already shows who the subject is.

• gosto = I like
• posso = I can
• ouço = I hear / I listen

So:

• Gosto de fones... = I like headphones... (the eu is understood)
• Posso caminhar... = I can walk...
• ... enquanto ouço um podcast. = while I listen to a podcast.

It’s not wrong to say the pronoun:

• Eu gosto de fones sem fios...
• Eu posso caminhar...
• ... enquanto eu ouço um podcast.

But in neutral, everyday European Portuguese, you usually drop eu unless:

• you want to emphasize the subject (I, not someone else), or
• there might be ambiguity without it.

Ouvir (to hear / to listen) is slightly irregular in the present tense.

Infinitive: ouvir

Present tense:

• eu ouço – I hear / I listen
• tu ouves – you (singular, informal) hear
• ele / ela / você ouve – he/she/you hear(s)
• nós ouvimos – we hear
• vocês / eles / elas ouvem – you (plural) / they hear

So the irregular form is mainly eu ouço:

• spelling change from uvir → ouço to keep the right sound.

Your sentence:

• enquanto ouço um podcast = while I listen to a podcast.

Yes, you can say both in European Portuguese:

1. ... enquanto ouço um podcast.

   • Simple present, but in Portuguese it can naturally refer to an action that is ongoing at that time.
   • Very common and perfectly natural.

2. ... enquanto estou a ouvir um podcast.

   • estar a + infinitive is the usual European Portuguese way to form a present continuous (similar to “am listening”).
   • Puts a bit more emphasis on the action being in progress.

In practice, in this kind of sentence, both are very natural. Many speakers will actually prefer the shorter enquanto ouço um podcast.

(Just note: in Brazil, the continuous is estar ouvindo; in Portugal, it’s estar a ouvir.)

Article choice:

• um podcast = a podcast (not a specific one; just any podcast)
• o podcast = the podcast (a specific, known podcast)

In your sentence, we’re talking about podcasts in general, so um podcast is natural.

Gender:

• podcast is treated as masculine in Portuguese:
  • um podcast, o podcast, este podcast.

Plural:

• podcasts (same spelling as in English), masculine plural:
  • dois podcasts, uns podcasts, os podcasts.

So your phrase ouço um podcast is grammatically correct and idiomatic in European Portuguese.