Muškarac modelira glinu.

Because glinu is the accusative singular form of glina.

In Muškarac modelira glinu, glina is the direct object: it is the thing being modeled. In Croatian, the direct object often goes into the accusative case.

• nominative: glina = clay
• accusative: glinu = clay (as the object of the verb)

So:

• Glina je mekana. = The clay is soft.
• Modelira glinu. = He is modeling clay.

Because muškarac is the subject of the sentence, so it is in the nominative case.

Here, muškarac is the person doing the action:

• Muškarac = the man
• modelira = models
• glinu = clay

So the subject stays in nominative:

• Muškarac modelira glinu.

If muškarac were an object, its form could change. For example, because it is a masculine animate noun, its accusative singular would be:

• muškarca

Modelira is the 3rd person singular present tense form of the verb modelirati.

That means it corresponds to:

• he models
• she models
• it models

Croatian present-tense verbs change depending on the subject. For modelirati, the present forms are:

• ja modeliram = I model
• ti modeliraš = you model
• on/ona/ono modelira = he/she/it models
• mi modeliramo = we model
• vi modelirate = you plural/formal model
• oni/one/ona modeliraju = they model

It can mean both, depending on context.

Croatian present tense often covers both:

• he models
• he is modeling

So Muškarac modelira glinu could mean:

• The man models clay.
• The man is modeling clay.

The wider context tells you which is more natural.

Because Croatian does not use articles like English the and a/an.

So:

• muškarac can mean a man or the man
• glinu can mean clay, the clay, or sometimes some clay, depending on context

Croatian relies on context, word order, and emphasis rather than articles.

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

The neutral order here is:

• Muškarac modelira glinu.

But you could also say:

• Glinu modelira muškarac.
• Modelira glinu muškarac.

These versions are grammatically possible, but they change the focus or emphasis.

For example:

• Muškarac modelira glinu. = neutral statement
• Glinu modelira muškarac. = emphasis on clay
• Modelira glinu muškarac. = can sound more marked or context-driven

You know from the case endings.

In this sentence:

• muškarac is nominative, so it is the subject
• glinu is accusative, so it is the object

That means even if you move the words around, the forms still tell you their roles.

For example:

• Muškarac modelira glinu.
• Glinu modelira muškarac.

Both still mean that the man is doing the modeling, and the clay is what is being modeled.

Yes. Croatian often omits the subject pronoun or noun if it is clear from the verb form or from context.

You could simply say:

• Modelira glinu.

That means:

• He/She is modeling clay or
• He/She models clay

However, if you specifically want to mention the man, then you keep muškarac in the sentence.

A simple English-friendly approximation is:

• muškarac ≈ moosh-kah-rahts

A few useful sound notes:

• š sounds like sh in shoe
• final c in Croatian usually sounds like ts

So:

• muš = moosh
• ka = kah
• rac = roughly rahts

A simple approximation is:

• glinu ≈ glee-noo

Sound notes:

• g is always a hard g, like in go
• li here is pronounced clearly, not like English lye
• u sounds like oo in food

So the whole word is close to glee-noo.

It is a borrowed/international-style verb, and it is perfectly normal Croatian.

Croatian has many verbs of this type, often ending in -irati, especially words connected with art, technology, or international vocabulary.

So modelirati means to model, to shape, or to sculpt/form, depending on context.

In this sentence, it means shaping clay with the hands or as part of sculpting.

Sometimes yes, but the meaning is slightly different.

• muškarac = a man, an adult male
• čovjek = a human being, a person, or sometimes a man depending on context

So:

• Muškarac modelira glinu. clearly means A/The man is modeling clay.
• Čovjek modelira glinu. can also mean A/The man is modeling clay, but it can feel a bit more like the person/man depending on context.

If you specifically want to emphasize male gender, muškarac is the clearer choice.

Yes, both nouns have grammatical gender, and that affects their forms.

• muškarac is masculine
• glina is feminine

That is why glina changes to glinu in the accusative singular: many feminine nouns ending in -a change that ending to -u in the accusative.

Examples:

• knjiga → knjigu
• žena → ženu
• glina → glinu

So this sentence is a good example of how noun gender and case work together in Croatian.