Si tinc mal de cap, no vull mirar la televisió.

Because after si meaning if, Catalan normally uses the indicative, not the subjunctive, for real or likely situations.

So:

• Si tinc mal de cap... = If I have a headache...

Using tingui here would sound wrong in standard Catalan.

A useful rule:

• si + present indicative for normal if clauses
• then another clause with present, future, imperative, etc.

Examples:

• Si plou, em quedo a casa. = If it rains, I stay home.
• Si tinc temps, t’ajudo. = If I have time, I’ll help you.

Catalan often leaves out subject pronouns when they are not needed, because the verb ending already shows the subject.

So:

• tinc already means I have
• vull already means I want

That means Si tinc mal de cap, no vull mirar la televisió is completely natural without jo.

You could say:

• Si jo tinc mal de cap, no vull mirar la televisió

But adding jo usually gives extra emphasis, like If I have a headache... with stress on I.

Mal de cap is the normal Catalan expression for headache.

Literally, it is something like:

• mal = pain / ache
• de cap = of head

Catalan often expresses physical pain this way:

• mal de cap = headache
• mal de coll = neck pain / sore neck
• mal d’esquena = backache
• mal de panxa = stomach ache

So even though English often uses a single noun like headache, Catalan commonly uses this expression with mal de...

Because tenir is the normal verb used with many physical states and symptoms in Catalan.

So Catalan says:

• tenir mal de cap = to have a headache
• tenir gana = to be hungry
• tenir set = to be thirsty
• tenir son = to be sleepy

This is very common, and it may feel different from English, but it is a standard Catalan pattern.

Yes. That is another very common way to express the same idea.

• Tinc mal de cap = I have a headache
• Em fa mal el cap = My head hurts / My head is hurting

Both are natural. The difference is mostly one of structure:

• tenir mal de cap focuses on having the pain
• fer mal focuses on the body part hurting

So you could also say:

• Si em fa mal el cap, no vull mirar la televisió.

That would be just as natural.

Because voler means to want, and it is followed directly by an infinitive.

So:

• vull mirar = I want to watch
• vull menjar = I want to eat
• vull dormir = I want to sleep

This is the same basic pattern as English want + infinitive, except English usually uses to:

• I want to watch
• Catalan: vull mirar

There is no extra word like to between the two verbs in Catalan.

Yes. In Catalan, mirar is commonly used for watch in contexts like TV.

So:

• mirar la televisió = to watch television

Catalan also has veure, which means to see, and in some contexts people also use it in ways that overlap with English watch. But for TV, mirar la televisió is a very standard and natural choice.

A simple distinction:

• mirar = to look at / watch
• veure = to see

Examples:

• Miro la televisió. = I watch TV.
• Veig la televisió des del sofà. = I see the television from the sofa.

Because Catalan usually uses the definite article with televisió in this expression.

So Catalan says:

• mirar la televisió

not usually:

• mirar televisió

This is one of those places where Catalan and English structure things differently. English often drops the article with media words, but Catalan commonly keeps it.

Compare:

• Escolto la ràdio. = I listen to the radio.
• Miro la televisió. = I watch television.

The comma separates the if-clause from the main clause:

• Si tinc mal de cap, = If I have a headache,
• no vull mirar la televisió. = I don’t want to watch television.

This is very normal punctuation when a conditional clause comes first.

If the main clause came first, the comma is often omitted:

• No vull mirar la televisió si tinc mal de cap.

Both versions are correct, but the original sentence puts the condition first.

Here it means I don’t want.

• vull = I want
• no vull = I do not want / I don’t want

It does not mean I won’t in the future sense. For I won’t, Catalan would normally use a future or a different structure depending on the context.

So in this sentence:

• no vull mirar la televisió = I don’t want to watch television

Not when it means a physical headache.

The normal expression is:

• mal de cap

However, there is also:

• maldecap

written as one word, which usually means worry, trouble, or headache in a figurative sense.

So:

• Tinc mal de cap. = I have a headache.
• Això em dona molts maldecaps. = That gives me a lot of headaches / problems.

This is a useful distinction to remember.

Yes, it can, depending on context.

Si usually means if, but sentences like this can sometimes be understood more generally, especially if they describe a habit or repeated situation.

So this sentence may mean:

• If I have a headache, I don’t want to watch television or
• Whenever I have a headache, I don’t want to watch television

If you wanted to make the habitual meaning more explicit, Catalan could use something like:

• Quan tinc mal de cap, no vull mirar la televisió. = When I have a headache, I don’t want to watch television.

Yes, vull can look strange to English speakers.

It is the 1st person singular form of voler:

• jo vull = I want

The ll in Catalan is traditionally a palatal sound, similar to the lli sound many learners hear in words like Spanish ll in some regions, though modern pronunciation varies by dialect.

The important thing for a beginner is:

• learn vull as the fixed form meaning I want
• don’t try to build it mechanically from the infinitive voler

Other forms are also irregular:

• vull = I want
• vols = you want
• vol = he/she wants
• volem = we want
• voleu = you all want
• volen = they want

So vull is just one of those forms worth memorizing early.