Školarina za napredni kurs je skupa.

Školarina means tuition or tuition fee—the money paid for education or instruction. In this sentence, it means the fee you pay for taking the course.

So:

• škola = school
• školarina = tuition / school fee

It does not mean school itself.

Here za means for.

So za napredni kurs means for the advanced course.

This prepositional phrase tells you what the tuition is for:

• školarina = tuition
• za napredni kurs = for the advanced course

It is in the accusative singular because the preposition za here takes the accusative.

So:

• za
  • accusative
• napredni kurs = accusative singular

Even though it looks the same as the dictionary form, grammatically it is accusative here.

Because kurs is a masculine inanimate noun, and in Serbian the accusative singular of masculine inanimate nouns is usually the same as the nominative singular.

So:

• nominative: napredni kurs
• accusative: napredni kurs

They look identical, even though the case has changed.

This is very common in Serbian.

A useful beginner rule is:

• before a noun, Serbian often uses the long form of the adjective
• as a predicate after je, the short form is often used

So:

• napredni kurs = advanced course
• Kurs je napredan. = The course is advanced.

That is why napredni kurs sounds natural here.

Because adjectives in Serbian must agree with the noun they describe.

The subject here is školarina, which is:

• feminine
• singular

So the adjective must also be feminine singular:

• masculine: skup
• feminine: skupa
• neuter: skupo

That is why the sentence has je skupa.

Here it means expensive.

That is because it is being used as an adjective with školarina:

• Školarina ... je skupa. = The tuition ... is expensive.

The form skupa can also mean together in other contexts, but not here.

So in this sentence, the meaning is clearly expensive.

Je is the 3rd person singular present tense of biti (to be), so it means is.

So:

• je = is

The structure is:

• Školarina za napredni kurs = subject
• je = is
• skupa = expensive

So literally: Tuition for the advanced course is expensive.

Because Serbian does not have articles like English the and a/an.

So Školarina za napredni kurs je skupa can be understood as:

• The tuition for the advanced course is expensive
• or Tuition for the advanced course is expensive

The exact English article depends on context, not on a separate Serbian word.

Not completely. Serbian word order is more flexible than English word order.

This sentence is a very natural, neutral way to say it:

• Školarina za napredni kurs je skupa.

You can move parts around for emphasis, for example:

• Za napredni kurs školarina je skupa.

That puts more emphasis on for the advanced course.

So the given sentence is the most straightforward version, but not the only possible one.