Želim nacrtati mačku u bilježnicu.

Croatian often leaves out subject pronouns when they are already clear from the verb form.

Here, želim means I want, so the I is built into the verb.
You could say Ja želim nacrtati mačku u bilježnicu, but ja would usually add emphasis, like I want to.

Želim is the 1st person singular present form of željeti, meaning to want.

After željeti, Croatian commonly uses an infinitive:

• želim nacrtati = I want to draw
• želim jesti = I want to eat
• želim spavati = I want to sleep

So the structure is:

želim + infinitive

This is an aspect question.

• crtati = imperfective, focusing on the process of drawing
• nacrtati = perfective, focusing on completing the drawing

So:

• Želim crtati mačku suggests I want to be drawing a cat / I want to draw cats as an activity
• Želim nacrtati mačku suggests I want to draw a cat and finish it

In this sentence, nacrtati is natural because it refers to completing one drawing.

Because it is the direct object of the verb, so it goes into the accusative case.

The base form is:

• mačka = cat

But after a verb like nacrtati, the thing being drawn is the object:

• nacrtati mačku = draw a cat

For many feminine nouns ending in -a, the accusative singular ends in -u:

• mačka → mačku
• žena → ženu
• knjiga → knjigu

Because after u, Croatian can use different cases depending on the meaning.

Here, u bilježnicu uses the accusative, which often expresses direction, destination, or the target of an action.

So the sentence treats the notebook as the place you are putting the drawing into.

• bilježnica = notebook
• u bilježnicu = into the notebook / in the notebook as the target surface or space for writing or drawing

This is very common with verbs like writing and drawing.

Yes, but the meaning shifts.

• u bilježnicu = into the notebook, with a sense of direction or target
• u bilježnici = in the notebook, describing location

With actions like writing or drawing, Croatian often prefers u + accusative when you mean putting something into a notebook, workbook, or similar space.

A useful contrast:

• Nacrtat ću to u bilježnicu. = I’ll draw it in/into the notebook.
• Crtež je u bilježnici. = The drawing is in the notebook.

So u bilježnicu fits the action better here.

Croatian has no articles, so there is no separate word for a or the.

That means mačku can mean:

• a cat
• the cat

The exact meaning usually comes from context.

If needed, Croatian can make things more specific with word order, context, or words like:

• jednu mačku = one/a certain cat
• tu mačku = that cat
• ovu mačku = this cat

Yes. Croatian word order is more flexible than English because case endings show what each word is doing.

The neutral order here is:

• Želim nacrtati mačku u bilježnicu.

But other orders are possible for emphasis:

• Mačku želim nacrtati u bilježnicu. = It’s the cat that I want to draw.
• U bilježnicu želim nacrtati mačku. = It’s in the notebook that I want to draw the cat.

So word order often affects emphasis more than basic grammar.

A rough guide:

• ž sounds like the s in measure
• č sounds like ch in church
• lj is a soft sound, similar to the lli in some pronunciations of million

Very roughly:

• Želim ≈ ZHE-lim
• mačku ≈ MATCH-koo
• bilježnicu ≈ bee-LYEZH-nee-tsoo

These are only approximations, but they are a good start for an English speaker.