Learn Hardcore Croatian: Na Svjetski dan životinja djeca idu u azil za životinje. - On World Animal Day, the children go to the animal shelter.

Na – on (preposition, here used with accusative to talk about a specific day/time)
Svjetski – world, global (adjective, masculine accusative singular, agreeing with dan)
dan – day (masculine accusative singular)
životinja – of animals (genitive plural of životinja = animal)
- Svjetski dan životinja literally: World day of animals
djeca – children (irregular plural of dijete = child; grammatically neuter plural, but behaves like a normal plural subject)
idu – go (3rd person plural present of ići = to go)
u – to / into (preposition, here with accusative because of movement)
azil – shelter (masculine accusative singular)
za – for (preposition, here with accusative)
životinje – animals (accusative plural of životinja)

So the key cases:

Svjetski dan – accusative (time expression with na)
životinja – genitive plural (day of animals)
djeca – nominative plural (subject)
azil – accusative (movement into)
životinje (after za) – accusative plural (for whom? → animals)

Why is the preposition na used in Na Svjetski dan životinja? Could I use u instead?

In time expressions, Croatian often uses na + accusative to mean on (a specific day / date / holiday):

na Božić – on Christmas
na Dan državnosti – on Statehood Day
na Svjetski dan životinja – on World Animal Day

Using u + locative with dan (u danu) is possible in other contexts, but it changes the meaning and sounds unusual here.

na dan → on the day (punctual, the calendar day/event)
u danu → in the day (inside the span of the day; very rarely used like this)

For names of holidays or special days, na + accusative is the normal, idiomatic choice. So Na Svjetski dan životinja is the natural way to say On World Animal Day.

Why is it dan životinja and not dan životinje? What is the form životinja here?

životinja in dan životinja is genitive plural of životinja (animal).

Compare:

nominative singular: životinja – an animal
genitive singular: životinje – of an animal
nominative plural: životinje – animals
genitive plural: životinja – of animals

The pattern dan + genitive plural is very common:

Dan žena – Day of Women
Dan učitelja – Teachers’ Day
Dan djece – Children’s Day

So Dan životinja = Day of Animals (i.e., animals in general), not Day of (one) animal, which would be Dan životinje.

Why does djeca take the plural verb idu, if djeca doesn’t look like a regular plural?

Djeca is the irregular plural of dijete (child).

singular: dijete ide – the child goes
plural: djeca idu – the children go

Even though djeca looks a bit different from a typical plural, grammatically it is a neuter plural noun, and in modern usage it normally takes 3rd person plural verb forms:

Djeca idu u školu. – The children go to school.
Djeca jedu. – The children are eating.

So djeca idu is exactly like English children go.

Could the word order be Djeca idu u azil za životinje na Svjetski dan životinja? Is the current order special?

Yes, Djeca idu u azil za životinje na Svjetski dan životinja is also grammatically correct.

Croatian word order is quite flexible. Putting Na Svjetski dan životinja at the beginning:

emphasizes when this happens
gives you a typical time–subject–verb–place rhythm:
- Na Svjetski dan životinja (time)
- djeca (subject)
- idu (verb)
- u azil za životinje (place/purpose)

So the chosen order sounds natural and slightly highlights the special day. The alternative order is fine but has a bit less emphasis on the day.

Why is it u azil and not u azilu? What’s the difference?

The preposition u can take either:

accusative – for movement into something
locative – for location in something

In the sentence, the children are going to the shelter (movement), so we use accusative:

idu u azil – they are going into/to the shelter

If we were talking about being in the shelter (no movement), we’d use locative:

Djeca su u azilu. – The children are in the shelter.

So:

u azil (accusative) → going there
u azilu (locative) → being there

Why is za životinje used after azil? Could I say azil životinja instead?

Azil za životinje literally means shelter for animals.

In Croatian, za + accusative is a very common way to express “for X”, especially when describing the target group or purpose:

škola za strance – school for foreigners
dom za starije – home for the elderly
knjiga za djecu – book for children

So:

azil za životinje – shelter for animals

You could theoretically say azil životinja (with životinja in genitive plural), but it would sound less natural and more like a technical label or a slightly awkward noun–noun compound. The standard, idiomatic phrase is azil za životinje.

What is the case and form of životinje in za životinje? It looks like the same as nominative plural.

You’re right: životinje is both:

nominative plural: životinje – animals
accusative plural: životinje – (for) animals / (towards) animals

After the preposition za, Croatian always uses the accusative. So in za životinje, životinje is accusative plural, even though it has the same form as the nominative plural.

Many feminine nouns in -a have identical nominative plural and accusative plural forms. Context (and the preposition) tells you the case.

Why is only Svjetski capitalized in Svjetski dan životinja? Why not all words?

In Croatian, with names of holidays, memorial days, etc., typically only the first word is capitalized:

Dan državnosti – Statehood Day
Međunarodni dan žena – International Women’s Day
Dan planeta Zemlje – Earth Day

If the first word is an adjective, that adjective is capitalized, and the rest remains lower-case (unless there’s a proper name like Zemlje):

Svjetski dan životinja – World Animal Day

So we write:

Svjetski dan životinja (only Svjetski capitalized, dan životinja lower-case)

Writing Svjetski Dan Životinja with every word capitalized would look English-influenced and is not standard Croatian.

How is the verb idu formed, and what are some other forms of ići?

Idu is 3rd person plural, present tense of the verb ići (to go). Ići is irregular. Present tense forms:

ja idem – I go
ti ideš – you go (singular)
on/ona/ono ide – he/she/it goes
mi idemo – we go
vi idete – you go (plural/formal)
oni/one/ona idu – they go

So djeca idu = the children go.

The infinitive is ići, but the present stem is id-, not i-, which is why you get idem, ideš, idu, not ićem, ićeš, iću.

Could I drop za životinje and just say djeca idu u azil?

Yes, grammatically you can say:

Na Svjetski dan životinja djeca idu u azil.

This would mean: On World Animal Day the children go to the shelter.

However:

azil by itself simply means shelter, asylum (could be political asylum, a shelter for refugees, etc.).
azil za životinje specifies an animal shelter.

In most real-life contexts, if you are talking about World Animal Day and azil, people will understand you mean an animal shelter, but adding za životinje makes it explicit and is more natural when teaching or in neutral description.

Is there any difference in meaning or style between Svjetski dan životinja and Dan životinja?

Yes:

Dan životinja – Day of Animals (could be any, generic day honoring animals)
Svjetski dan životinja – World Animal Day, a specific internationally recognized day (October 4).

Adding Svjetski (world, global) makes it clear that this is the official international day, not just any “animal day” a school or town might create.

How do you pronounce Svjetski and životinja? The svj cluster and ž are unfamiliar.

Approximate pronunciation (IPA-like, but written simply):

Svjetski → [svyets-kee]
- svj: say s
  - v quickly, then a je sound → svje
- stress is usually on the first syllable: SVJEt-ski
životinja → [zhee-VOH-tee-nyah]
- ž like the s in measure or vision
- ti before nj comes out a bit like “tee” but soft
- nj similar to ñ in Spanish niño
- stress: ži-VÓ-ti-nja (main stress on vo; in practice, learners are usually understood even if they just stress the first syllable: ŽI-vo-ti-nja).

Perfect, authentic stress is less important at the beginning; focus on getting ž, nj, and the consonant clusters reasonably clear.