יש לי כאב ראש, ולכן אני לא רוצה לשמוע מוזיקה.

In Modern Hebrew, possession is very often expressed with יש ל־... rather than with a separate verb to have.

So:

יש לי = literally there is to me
Natural English meaning: I have

In your sentence:

יש לי כאב ראש = literally There is to me a headache
Natural English: I have a headache

This is a very common pattern:

• יש לי זמן = I have time
• יש לה אוטו = She has a car
• יש להם שאלה = They have a question

The negative form is important too:

• אין לי כאב ראש = I do not have a headache

So Hebrew treats possession more like existence + to someone.

כאב ראש means headache.

Literally, it is something like head pain or pain of the head:

• כאב = pain
• ראש = head

Together they form a very common fixed expression for headache.

So although an English speaker may expect something more like pain in the head, Hebrew normally uses כאב ראש as the standard noun phrase.

For learning purposes, it is best to treat כאב ראש as a fixed vocabulary item meaning headache.

Yes, you can notice that it looks like a noun combination, but in everyday use, learners usually just memorize it as one expression.

That is helpful because Hebrew has many similar combinations that act almost like single words. If you stop every time to analyze the structure, it can slow you down. So the easiest approach is:

כאב ראש = headache

Later, as your Hebrew improves, you can learn more about noun combinations and construct-style phrases.

Hebrew has no separate word for a or an.

So כאב ראש by itself can mean a headache depending on context.

In this sentence:

יש לי כאב ראש = I have a headache

If you wanted the headache, Hebrew would usually show definiteness with ה־:

• כאב הראש = the headache

But in your sentence, the indefinite meaning a headache is exactly what is needed, so no article appears.

ולכן means and therefore, and so, or simply so.

It is made of:

• ו־ = and
• לכן = therefore / so

So:

יש לי כאב ראש, ולכן... = I have a headache, so...

A learner should know that לכן is slightly more formal or more written-sounding than very casual אז. But it is still completely normal and correct.

So these all relate in meaning:

• ולכן = and therefore / so
• אז = so / then

In this sentence, ולכן sounds clear and natural.

Yes, אני could sometimes be omitted in Hebrew, but here it is very natural to include it.

The reason is that in the present tense, Hebrew verbs often do not clearly show person by themselves. The form רוצה tells you gender and number, but not by itself as clearly as English I want does.

So:

• אני לא רוצה = I do not want
• לא רוצה = do not want / not wanting

Without אני, the sentence can still work in conversation if the subject is obvious, but אני makes it clear and complete.

So for learners, including אני is the safest and most standard choice here.

In Hebrew, לא is the normal word for not, and it usually comes before the verb or verbal expression.

So:

• אני רוצה = I want
• אני לא רוצה = I do not want

That word order is standard.

This is worth comparing with the first part of the sentence:

• יש לי = I have
• negative: אין לי, not לא יש לי

So Hebrew uses different negative patterns in different structures:

• ordinary negation: לא
• negative existence / possession: אין

That is why the sentence has both:

• יש לי כאב ראש
• אני לא רוצה לשמוע מוזיקה

Because Hebrew commonly uses רוצה + infinitive to mean want to do something.

So:

• רוצה = want
• לשמוע = to hear / to listen

Together:

רוצה לשמוע = want to hear / want to listen

This is a very common pattern:

• אני רוצה לאכול = I want to eat
• אני רוצה ללמוד = I want to study
• אני רוצה לישון = I want to sleep

So once you learn רוצה + infinitive, you can use it with many verbs.

It can mean either, depending on context.

The basic verb is שמע, and לשמוע can cover both:

• to hear
• to listen

In your sentence, because the object is music, English naturally translates it as listen to music:

אני לא רוצה לשמוע מוזיקה = I don’t want to listen to music

If you want to emphasize active listening or paying attention, Hebrew also has:

להקשיב ל־... = to listen to ...

For example:

• להקשיב למוזיקה = to listen to music

But לשמוע מוזיקה is very common and natural Hebrew.

Because לשמוע usually takes a direct object in Hebrew.

So Hebrew says:

• לשמוע מוזיקה = to hear / listen to music

Even though English uses the preposition to in listen to music, Hebrew does not need a preposition here.

That is a very common thing for English speakers to notice: Hebrew and English do not always use the same prepositions, and sometimes Hebrew uses none at all.

So just remember this as the normal pattern:

לשמוע + thing

• לשמוע שיר = to hear a song
• לשמוע חדשות = to hear the news
• לשמוע מוזיקה = to listen to music

Because את is used only before a definite direct object.

In this sentence, מוזיקה is being used in a general sense, like music in English, not the music. So there is no את.

Compare:

• לשמוע מוזיקה = to listen to music
• לשמוע את המוזיקה = to listen to the music

So the rule is:

• indefinite or general object: usually no את
• definite object: use את

That is why מוזיקה appears by itself here.

Yes. In the present tense, Hebrew usually marks gender.

So I want is:

• masculine speaker: אני רוצה
• feminine speaker: אני רוצה

In normal unpointed spelling, they look the same. The difference is in pronunciation:

• masculine: rotze
• feminine: rotza

So the written sentence can be used by either a male or a female speaker. You understand the gender from context or from hearing it spoken.

That is a very common feature of Hebrew present-tense forms.