Learn Hardcore Portuguese (Portugal): Sempre que estou cansado, ouço música.

You can say Eu, sempre que estou cansado, ouço música, but it sounds more emphatic (for contrast: "As for me, whenever I'm tired, I listen to music").

Why is it sempre que and not just quando? Are they the same?

Both sempre que and quando can be translated as whenever / when, but:

sempre que = every time that, whenever
- Emphasises repetition or a habit.
- Sempre que estou cansado, ouço música.
  → Every time I’m tired, I listen to music.
quando = when
- More neutral. Can refer to one time or repeated times, depending on context.
- Quando estou cansado, ouço música.
  → Context decides if it means when I’m tired (in general) or when I happen to be tired.

In your sentence, sempre que makes the habitual meaning very clear: it’s what you always do in that situation.

Why is there a comma after cansado? Is it necessary?

Yes. In European Portuguese, it is standard to separate a dependent clause at the beginning of the sentence from the main clause with a comma:

Sempre que estou cansado, ouço música.
- Dependent clause: Sempre que estou cansado
- Main clause: ouço música

If you reverse the order, you normally do not use a comma:

Ouço música sempre que estou cansado. (no comma)

So the comma is not random; it reflects the clause structure.

Why is it estou cansado and not sou cansado?

Portuguese has two verbs for to be:

ser – more permanent or defining characteristics.
estar – temporary states, conditions, locations, emotions.

Being tired is a temporary state, so you use estar:

Estou cansado. → I’m (feeling) tired now / at that time.

Sou cansado is very unusual and would suggest something like:

I’m a tired kind of person by nature (almost like a personality trait), and even then, people would normally phrase it differently.

So:

estou cansado – correct and natural here.
sou cansado – basically wrong in this context.

Why is it cansado and not something like cansada or cansados?

Adjectives in Portuguese agree with the gender and number of the subject.

Here the subject is eu:

If the speaker is male:
→ estou cansado
If the speaker is female:
→ estou cansada

For plural:

Group of males or mixed group: estamos cansados
Group of only females: estamos cansadas

So the sentence given assumes a male speaker. For a female speaker, the full sentence would be:

Sempre que estou cansada, ouço música.

Can I move sempre que estou cansado to the end and say Ouço música sempre que estou cansado?

Yes, that is perfectly correct and very natural:

Ouço música sempre que estou cansado.

Both orders are fine:

Sempre que estou cansado, ouço música.
Ouço música sempre que estou cansado.

The meaning is the same; it’s just a different emphasis. Putting the sempre que clause first slightly highlights the condition (whenever I’m tired). Putting ouço música first focuses slightly more on the action (I listen to music).

What form of the verb is ouço? Why is it not ouvir or ouvo?

Ouço is the 1st person singular, present tense of the verb ouvir (to hear / to listen to).

Infinitive: ouvir
Eu: ouço
Tu: ouves
Ele / Ela / Você: ouve
Nós: ouvimos
Eles / Elas / Vocês: ouvem

The spelling ouço reflects a sound change; historically it comes from an older form, so you can’t build it mechanically as ouvo.
*ouvo is incorrect in standard Portuguese.

So:

Eu ouço música. → I listen to music / I hear music.

Does ouvir mean “to hear” or “to listen to”? Is escutar different?

In Portuguese:

ouvir – literally to hear, but commonly also used as to listen to, especially with music.
- Ouço música. → I listen to music.
escutar – closer to to listen (attentively).
- Escuto o que dizes. → I listen to what you say.

In European Portuguese, for talking about music, ouvir música is the most common expression.
You can say escutar música, but ouvir música is more idiomatic and frequent.

Why is it ouço música and not ouço a música or ouço músicas?

All three are possible, but they mean slightly different things:

Ouço música.
- General, uncountable sense: I listen to music (in general, as an activity/habit).
Ouço a música.
- Refers to a specific piece / the specific music that is known from context.
- Example: There is music playing somewhere and you say:
  - Ouço a música. → I hear the music.
Ouço músicas.
- Plural, like I listen to songs / I listen to different tracks.
- More often used with a qualifier:
  - Ouço músicas brasileiras. → I listen to Brazilian songs.

In your sentence, the habitual activity is being described, so ouço música (no article, singular) is the natural choice.

Why is the present tense (estou, ouço) used for a habitual action? Shouldn’t there be a special tense like in some languages?

Portuguese uses the simple present to express:

actions happening now:
- Estou cansado. → I am tired (now).
habitual or repeated actions:
- Ouço música todos os dias. → I listen to music every day.
- Sempre que estou cansado, ouço música. → Whenever I’m tired, I listen to music.

So using the present here is completely normal and works just like English:

English: Whenever I’m tired, I listen to music.
Portuguese: Sempre que estou cansado, ouço música.

How do you pronounce ouço and sempre in European Portuguese?

Approximate European Portuguese pronunciation:

ouço → roughly “OH-soo”
- ou- like oh
- -ço with an “s” sound (because of ç), plus an unstressed u that is very short.
sempre → roughly “SEMP-ruh”
- sem- like English sem- in “semi”, but the e is shorter.
- -pre: the p is pronounced; the r is a light single tap; the final e is a very short “uh” sound.

Native European Portuguese speech is often quite reduced, so the vowels, especially at the end of words, are short and less clear than in English.