Learn Hardcore Croatian: Danas je vjetar slab.

Croatian word order is more flexible than English; the grammatical roles are marked mostly by endings, not position. Here, vjetar is clearly the subject, and slab is the predicate adjective describing it.

Why do we need je in this sentence? Can I drop it like in some other languages?

je is the 3rd person singular present tense of biti (to be). It corresponds to English is:

On je slab. – He is weak.
Vjetar je slab. – The wind is weak.

In normal, full sentences you must use je. Without it, the sentence sounds like a telegram or a headline:

Danas vjetar slab. – possible in a headline, weather chart, note on a board etc., but not standard conversational speech.

So, for everyday spoken or written Croatian, keep je:

Danas je vjetar slab. – correct, neutral, complete sentence.

What case is vjetar in, and why isn’t it vjetra here?

vjetar is in the nominative singular, because it is the subject of the sentence – the thing we’re talking about.

Basic forms of vjetar (wind):

Nominative singular (subject): vjetar
Genitive singular (of the wind): vjetra
Accusative singular (direct object, mostly): vjetar
Dative/locative singular: vjetru
Instrumental singular: vjetrom

You use vjetar (nominative) when wind is the subject:

Vjetar je jak. – The wind is strong.
Vjetar puše. – The wind blows.

You would use vjetra when wind is in the genitive, for example:

Nema vjetra. – There is no wind.
Zvuk vjetra. – The sound of the wind.

Here, because the wind is weak is a description of the subject, vjetar must be nominative.

Why is it slab and not slabo at the end?

slab is an adjective agreeing with the noun vjetar:

vjetar is masculine, singular, nominative.
The adjective describing it must also be masculine singular nominative: slab.

So:

slab vjetar / vjetar je slab – weak/light wind.

slabo is either:

The adverb – weakly, poorly
- On slabo govori hrvatski. – He speaks Croatian poorly.
The neuter singular form of the adjective (for neuter nouns)
- More je slabo. (not very natural here, but grammatically: The sea is weak).

With vjetar (masculine), the correct agreeing form is slab, not slabo:

✅ Danas je vjetar slab.
❌ Danas je vjetar slabo. (wrong if you mean the wind is weak).

Can I change the word order, for example Vjetar je danas slab or Vjetar je slab danas? Does the meaning change?

All of these are grammatically correct and mean essentially the same:

Danas je vjetar slab.
Vjetar je danas slab.
Vjetar je slab danas.

The differences are in emphasis and flow:

Danas je vjetar slab.
Starts with danas, so it slightly emphasizes today:
- Today, the wind is weak (as opposed to other days).
Vjetar je danas slab.
Starts with vjetar, so it makes the wind the first topic:
- The wind is weak today (as opposed to other conditions today).
Vjetar je slab danas.
Very similar to #2; putting danas at the end can sound a bit more contrastive or afterthought-like, depending on context.

In everyday speech, #1 and #2 are probably the most common and feel neutral. Word order in Croatian is flexible, but shifting elements affects what you’re highlighting, not the basic meaning.

Can I say Danas je slab vjetar instead? Does that sound natural?

You can say:

Danas je slab vjetar.

This is also grammatically correct. The nuance is:

Danas je vjetar slab.
= Today the wind is weak. (stating a property of the wind)
Danas je slab vjetar.
= Today there is weak wind. or Today it’s a weak wind.
Here slab vjetar functions more like a noun phrase (weak wind) being introduced.

The second version feels a bit more like you’re talking about a kind of wind that there is today, while the first feels more like a straightforward description of the current wind. Both are acceptable in speech; Danas je vjetar slab is the most neutral, textbook-like form.

How do I turn Danas je vjetar slab into a yes–no question like “Is the wind weak today?” in Croatian?

Common standard options:

Je li danas vjetar slab? – neutral, standard
Je li vjetar danas slab? – equally fine
Da li je danas vjetar slab? – very common in speech, somewhat less formal in writing

Notes:

Je li is the standard way to form yes–no questions with je.
Word order after je li is still flexible for emphasis, just like in statements.

Answers to such a question would be:

Da, danas je vjetar slab. – Yes, the wind is weak today.
Ne, danas vjetar nije slab. – No, the wind is not weak today.

What gender is vjetar, and how does that affect slab?

vjetar (wind) is masculine.

That determines the form of adjectives that agree with it:

slab vjetar – weak/light wind
jak vjetar – strong wind
hladan vjetar – cold wind
topao vjetar – warm wind

In the sentence Danas je vjetar slab, the adjective slab must match:

gender: masculine
number: singular
case: nominative

So you get masculine singular nominative slab.

If the noun were feminine or neuter, the adjective would change:

oluja je slaba – the storm is weak (feminine)
more je mirno – the sea is calm (neuter)

When would I use slabo with “wind”? Is there a structure where slabo is correct?

Yes. Use slabo when you want an adverb, describing how the wind blows, not what the wind is:

Danas vjetar slabo puše.
– Today the wind is blowing weakly / only a little.

Here:

vjetar – subject
puše – verb (blows)
slabo – adverb modifying the verb (how it blows)

Compare:

Danas je vjetar slab. – The wind is weak today. (adjective slab describing the noun)
Danas vjetar slabo puše. – Today the wind blows weakly. (adverb slabo describing the verb)

Both are correct, but they have slightly different structures and focus.

Why is there no word for “the” in vjetar? How do I know it means “the wind” and not “a wind”?

Croatian (like many Slavic languages) has no articles (a, an, the). The noun vjetar can mean:

the wind
a wind
just wind in general

Which one you choose in English depends on context, not on any extra Croatian word:

Danas je vjetar slab.
→ Today the wind is weak. (there is a specific wind today)
Vjetar je neugodan.
→ The wind is unpleasant.

If you really need to stress that you mean “this particular wind” or “that wind”, you can add a demonstrative:

Ovaj vjetar je slab. – This wind is weak.
Onaj vjetar je bio jak. – That wind was strong.

How do I pronounce vjetar, and where is the stress?

vjetar is pronounced approximately like:

[vye-tar]

Details:

vj is pronounced like English vy in vying, not like vj separately.
e is like e in bet.
t is a clean [t], without aspiration like in English top.
a is like a in father, but shorter.
r is rolled or tapped, like in Spanish or Italian.

Stress in standard Croatian is usually on the first syllable here:

VJE-tar

So: VJE-tar, not vje-TAR.

How would I say “Today the wind is very weak” or “a bit weak” in Croatian?

You can modify slab with adverbs:

Danas je vjetar jako slab.
– Today the wind is very weak.
Danas je vjetar dosta slab.
– Today the wind is quite weak.
Danas je vjetar pomalo slab.
– Today the wind is a bit weak.

You keep the same structure:

Danas je vjetar + [adverb] + slab.

The adjective slab still agrees with vjetar, and the adverb (e.g. jako) just modifies how strong or weak that quality is.