Learn Hardcore Croatian: Taj svjetski dan nam je važan.

Taj – that (demonstrative adjective, masculine singular, nominative)
svjetski – world / global (adjective, masculine singular, nominative)
dan – day (noun, masculine singular, nominative)
nam – to us / for us (unstressed dative plural form of mi = we)
je – is (3rd person singular of biti = to be)
važan – important (adjective, masculine singular, nominative, used as the predicate)

So the structure is literally: That world day to-us is important.

Why is nam used, and what does it mean grammatically?

Nam is the dative plural of the pronoun mi (we), in its short, unstressed (clitic) form.

mi – we (nominative)
nas – us (accusative/genitive)
nama – to/for us (dative, stressed form)
nam – to/for us (dative, short/clitic form)

In this sentence, nam answers the question “To whom is that day important?” → To us.
Croatian uses the dative case (without a preposition) where English uses to + pronoun:

Taj svjetski dan nam je važan.
That world day is important to us.

Why is there no separate word for “to” before nam, like in English “to us”?

Croatian often expresses ideas like “to someone” by using the dative case on the noun or pronoun, without a preposition.

English: to us
Croatian: nam (dative form of mi, no preposition needed)

So the function of English “to” is built into the word ending / form (nam) rather than a separate word.
Other similar examples:

Njemu je hladno. – He is cold. (literally: To him is cold.)
Djeci je dosadno. – The children are bored. (literally: To the children is boring.)

What is the difference between nam and nama?

Both mean “to us / for us” (dative plural of mi), but:

nam – short, unstressed clitic form; must appear in a special position in the sentence (the “second position” rule):
- Taj svjetski dan nam je važan.
nama – full, stressed form; can be placed more freely, often used for emphasis:
- Nama je taj svjetski dan važan. – It is to us that this World Day is important. (stronger emphasis on us)

Meaning is basically the same; nama just highlights “us” more strongly, while nam is the neutral, typical choice inside the sentence.

Why is the word order Taj svjetski dan nam je važan and not Taj svjetski dan je nam važan?

Because nam is a clitic (short unstressed word) and Croatian clitics obey a fairly strict word-order rule:

They like to come in “second position” in the sentence (after the first stressed word or phrase).
Within the clitic group, their internal order is fixed.

In Taj svjetski dan nam je važan:

The first stressed phrase is Taj svjetski dan.
After that, we get the clitic group nam je.
Then comes the rest (važan).

Putting it as je nam (Taj svjetski dan je nam važan) breaks the normal clitic order and sounds clearly wrong/unnatural to native speakers. You should say nam je, not je nam, in this kind of sentence.

Can I move nam and say Taj nam je svjetski dan važan or Nama je taj svjetski dan važan? Do they mean the same thing?

Yes, both are correct, and they all mean essentially the same thing, but with slightly different emphasis:

Taj svjetski dan nam je važan.
– Neutral, straightforward: “That World Day is important to us.”
Taj nam je svjetski dan važan.
– Still natural; by putting nam je earlier, you slightly highlight “to us” while keeping the focus quite broad. Common in speech.
Nama je taj svjetski dan važan.
– Strongest emphasis on nama (“to us”):
“For us that World Day is important.” (maybe implying: for others it might not be)

So: all correct, same core meaning, different nuances in focus and emphasis.

What case is Taj svjetski dan, and how do the words agree?

Taj svjetski dan is in the nominative singular masculine, because it’s the subject of the sentence.

Taj – demonstrative adjective, nominative masculine singular (agrees with dan)
svjetski – adjective, nominative masculine singular (agrees with dan)
dan – noun, nominative masculine singular

And the predicate adjective važan is also nominative masculine singular, agreeing with the subject dan:

Taj svjetski dan … je važan.

So all of these match in gender (masculine), number (singular) and case (nominative).

Why is it važan and not važno or važna?

In Croatian, adjectives used as predicates must agree with the subject in gender, number, and case.

Subject: dan – masculine, singular, nominative
Predicate adjective: must also be masculine singular nominative

So:

Taj svjetski dan … je važan. – correct (masculine singular)
… je važno. – neuter form (would mismatch the subject)
… je važna. – feminine form (would also mismatch)

If the subject changed, the adjective would change too:

Ta svjetska noć nam je važna. – noć (night) is feminine → važna
Ta svjetska sela su nam važna. – sela (villages) neuter plural → važna (neuter plural form, same surface form as fem. sg. but different agreement)

What gender is dan, and how can I recognize it?

Dan (day) is masculine.

Clues:

Many masculine nouns in Croatian end in a consonant (like dan, grad, stol).
It takes masculine agreement:
- dobar dan – good day (masc. adj. dobar)
- važan dan – important day (masc. adj. važan)
In the nominative plural it becomes dani, which is typical for masculine nouns.

So when you see svjetski dan, you know both words must be in the masculine form.

Why is svjetski in front of dan instead of after it?

In Croatian, adjectives normally come before nouns, just as in English:

svjetski dan – world day
važan dan – important day
lijep grad – beautiful city

Putting the adjective after the noun is unusual and usually only done in special stylistic or poetic contexts. So:

svjetski dan (normal)
dan svjetski (poetic / marked, not neutral speech)

For everyday speech and writing, always put adjectives before the noun.

Does taj mean “this” or “that”? How is it different from ovaj and onaj?

Croatian has three basic demonstratives:

ovaj – this (near the speaker)
taj – that (near the listener or previously mentioned / contextually given)
onaj – that (far from both speaker and listener; more distant or more clearly separated in context)

In practice, taj often corresponds to English “that”, but it’s also commonly used for something already known in the conversation or text:

Taj svjetski dan – that World Day we’re talking about / that particular World Day.

All three (ovaj, taj, onaj) behave like adjectives and must agree in gender, number, and case with the noun:

taj svjetski dan – that world day (masc. sg.)
ta svjetska noć – that world night (fem. sg.)
to svjetsko selo – that world village (neut. sg.)

Why isn’t svjetski capitalized, even though this is about a “World Day”?

In Croatian, capitalization works a bit differently from English:

In normal text, adjectives like svjetski (world, global) are written in lowercase, even when referring to official “World Days”, unless you’re writing the full official name of the event starting with that word.

So:

Taj svjetski dan nam je važan. – generic mention, lowercase svjetski and dan.
Svjetski dan učitelja nam je važan. – here Svjetski is capitalized because it’s the first word of the official name Svjetski dan učitelja (World Teachers’ Day).
In the middle of a sentence you might still see:
Taj Svjetski dan učitelja nam je važan.

In your sentence, svjetski dan is used descriptively, not as the full formal name, so lowercase is expected.

Is there a difference between Taj svjetski dan nam je važan and Važan nam je taj svjetski dan?

Both are grammatically correct and mean the same thing overall, but they differ in focus:

Taj svjetski dan nam je važan.
– Neutral, topic-first: we start from “that world day” and then state it is important to us.
Važan nam je taj svjetski dan.
– Focus on the quality “važan” (important); as if answering “Is that World Day important to you?”
– Literally: Important to us is that World Day.

So both translate as “That World Day is important to us”, but the second version stresses the importance more strongly.