Nije važno da li je restoran mali; važno je da je hrana dobra.

Because it is the standard negative form of je (is) in the present tense of biti (to be).

So:

• je = is
• nije = is not

This is very common in Serbian. The present-tense negative forms of biti are fused into single words:

• nisam = I am not
• nisi = you are not
• nije = he/she/it is not
• nismo = we are not
• niste = you plural/formal are not
• nisu = they are not

So Nije važno literally corresponds to It is not important, but without an expressed it.

Because važno is being used impersonally.

In English, we say It is important... The word it is just a dummy subject; it does not refer to a real thing. Serbian often does the same idea without a real subject, and in that structure the adjective usually appears in the neuter singular form.

So:

• važan = masculine singular
• važna = feminine singular
• važno = neuter singular

Here, važno je means it is important in an impersonal sense.

The same pattern appears in many expressions:

• Lepo je ovde. = It is nice here.
• Teško je učiti. = It is hard to study.
• Važno je da dođeš. = It is important that you come.

Here da li means whether.

So da li je restoran mali means whether the restaurant is small.

This is not a direct yes/no question here. It is an embedded question or indirect question inside a larger sentence.

Compare:

• Da li je restoran mali? = Is the restaurant small?
• Nije važno da li je restoran mali. = It is not important whether the restaurant is small.

A common learner mistake is to think da li always means a direct question. It can do that, but it is also used inside sentences to mean whether.

Sometimes yes in English, but whether is usually more precise.

English often uses if and whether in similar situations:

• It doesn’t matter if the restaurant is small.
• It doesn’t matter whether the restaurant is small.

In Serbian, da li here clearly introduces a yes/no possibility, so whether is the clearest explanation.

Be careful not to confuse this with ako, which usually means if in the sense of a condition:

• Ako je restoran mali, ipak ćemo ići. = If the restaurant is small, we will still go.

That is conditional if, not whether.

Because the embedded clause still needs its own verb: je = is.

The clause restoran je mali means the restaurant is small.
When that clause becomes embedded after da li, the verb is still there:

• da li je restoran mali

So the structure is:

• da li = whether
• je = is
• restoran mali = the restaurant small

English also keeps the verb inside the embedded clause:

• whether the restaurant is small

Here da introduces a content clause after važno je.

So:

• Važno je da je hrana dobra.
• literally: It is important that the food is good.

This da often corresponds to English that after expressions like:

• važno je = it is important
• dobro je = it is good
• šteta je = it is a shame
• moguće je = it is possible

Examples:

• Dobro je da si ovde. = It is good that you are here.
• Moguće je da kasni. = It is possible that he/she is late.

So the sentence uses da because Serbian normally links this kind of clause that way.

Because that subordinate clause also has its own verb.

Inside the clause:

• hrana je dobra = the food is good

After da, the clause stays a full clause:

• da je hrana dobra

So the sentence has two different je forms doing two different jobs:

1. važno je = it is important
2. da je hrana dobra = that the food is good

This is completely normal in Serbian.

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

Here:

• restoran is masculine singular
• hrana is feminine singular

So:

• restoran je mali = the restaurant is small
• hrana je dobra = the food is good

That is why you get:

• mali for masculine singular
• dobra for feminine singular

If the noun changed, the adjective would change too:

• mesto je malo = the place is small
• sobe su male = the rooms are small
• jelo je dobro = the dish/meal is good

Because this is a predicate adjective, not an adjective directly attached to the noun inside a noun phrase.

Compare:

• mali restoran = a small restaurant
• restoran je mali = the restaurant is small

In your sentence, the idea is not just naming a small restaurant. It is making a statement about the restaurant: it is small.

So after je, Serbian uses the adjective as part of the predicate:

• je restoran mali
• je hrana dobra

This is similar to English the restaurant is small, not the small restaurant.

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

So restoran can mean:

• a restaurant
• the restaurant
• sometimes just restaurant in a general sense

And hrana can mean:

• food
• the food

The exact meaning depends on context.

That is very normal in Serbian, and learners have to get used to understanding definiteness from the situation rather than from an article.

The semicolon separates two closely related independent clauses:

• Nije važno da li je restoran mali
• važno je da je hrana dobra

It helps show a strong contrast:

• not important: the restaurant being small
• important: the food being good

A semicolon is a neat written way to connect two balanced ideas. In less formal writing, you might also see a comma or a dash, depending on style.

Because those clauses are tightly connected to the expressions nije važno and važno je.

In Serbian, a comma is not automatically used before every subordinate clause the way English learners might expect. Here the clauses function as essential complements:

• nije važno da li...
• važno je da...

So the punctuation is normal without commas there. The main pause in the sentence is shown by the semicolon between the two larger parts.

Yes, to some extent. Serbian word order is flexible, though not random. Different orders can sound more neutral, more emphatic, or more literary.

The version you have is very natural and balanced:

• Nije važno da li je restoran mali; važno je da je hrana dobra.

You could also say:

• Važno je da je hrana dobra; nije važno da li je restoran mali.

That changes the emphasis by putting the important point first.

Inside the clauses, word order can sometimes shift too, but the standard neutral order here is good for learners.

Yes. Važno and bitno are often very close in meaning.

So you could say:

• Nije bitno da li je restoran mali; bitno je da je hrana dobra.

That sounds natural too.

Very roughly:

• važno = important
• bitno = important / essential / what matters

In many everyday contexts, they are interchangeable. Bitno je can sometimes feel a little more like what matters is..., but the difference is often small.

It is perfectly natural and can be used in everyday speech.

The semicolon makes the written sentence look a bit polished, but the structure itself is normal spoken Serbian too. In speech, someone might simply say it with a pause:

• Nije važno da li je restoran mali. Važno je da je hrana dobra.

That may be even more common in conversation.

So the grammar is standard and useful, not just literary.