Škola je velika, a njezin ulaz je desno.

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

So:

• škola can mean school or the school
• ulaz can mean entrance or the entrance

The exact meaning usually comes from context. If you really need to be more specific, Croatian can use other words, such as demonstratives:

• ta škola = that/the school
• taj ulaz = that/the entrance

Because Croatian adjectives must agree with the noun they describe in gender, number, and case.

• škola is feminine singular
• so the adjective must also be feminine singular
• therefore: velika

Compare:

• velik ulaz = a big entrance (masculine)
• velika škola = a big school (feminine)
• veliko selo = a big village (neuter)

A is a coordinating conjunction that often connects two ideas with a contrast or a shift of topic.

Depending on context, it can sound like:

• and
• while
• but

In this sentence, a is best understood as something like:

• and
• or while/as for

So Škola je velika, a njezin ulaz je desno suggests:

• The school is big, and its entrance is on the right with a slight sense of moving to a second piece of information.

It is not as strongly contrastive as ali (but).

There are two clauses here:

1. Škola je velika
2. njezin ulaz je desno

Each clause needs its own form of to be, so je appears twice.

Also, je is a clitic in Croatian. Clitics usually go in second position in their clause, after the first stressed word or phrase.

So:

• Škola je velika
• njezin ulaz je desno

That placement is very normal in Croatian.

Njezin means her or its, depending on context.

Here it refers back to škola. Since škola is a feminine noun, Croatian uses the feminine possessive stem:

• njezin ulaz = its entrance

This can feel strange to English speakers, because English usually uses it for things. Croatian follows grammatical gender, not natural gender.

So even though a school is not female in real life, the noun škola is grammatically feminine, and that affects the possessive form.

Because the possessive pronoun must agree with the thing possessed, not just the owner.

Here:

• the owner is škola (feminine), so we use the stem njezin-
• the possessed thing is ulaz (masculine singular nominative)

So the correct form is:

• njezin ulaz

Compare:

• njezin ulaz = her/its entrance (masculine noun)
• njezina škola = her school (feminine noun)
• njezino ime = her/its name (neuter noun)

Yes. That is also correct.

You can say:

• njezin ulaz = its entrance
• ulaz škole = the entrance of the school / the school's entrance

Both are natural. The version with njezin avoids repeating škola and sounds a bit smoother in connected speech.

Here desno is an adverb, not an adjective.

It means:

• on the right
• to the right

So:

• Ulaz je desno = The entrance is on the right

If you used desna, that would be an adjective meaning right in the sense of right-hand or located on the right, and it would need a noun:

• desna strana = the right side
• desna vrata = the right door

So in this sentence, desno is correct because it describes where the entrance is.

In this sentence:

• škola = nominative singular
  It is the subject of the first clause.

• velika = nominative singular feminine
  It agrees with škola.

• njezin ulaz:

  • ulaz = nominative singular
  • njezin = nominative singular masculine

  Together they form the subject of the second clause.

• desno is an adverb, so it does not have case.

This is a good example of a simple subject + je + complement structure in both clauses.

Because a is linking two independent clauses:

• Škola je velika
• njezin ulaz je desno

In standard Croatian, a comma is normally written before conjunctions like a, ali, and nego when they connect full clauses.

So the comma here is completely standard.

Yes, Croatian word order is fairly flexible, but the original version is a very neutral and natural one.

This sentence:

• Škola je velika, a njezin ulaz je desno.

is straightforward and clear.

Other versions are possible, but they may change the emphasis. For example:

• Velika je škola, a njezin ulaz je desno.
  More emphasis on big.

• Škola je velika, a desno je njezin ulaz.
  More emphasis on on the right.

So yes, the word order can change, but the original is probably the best basic version for a learner to copy.