Postoji mogućnost da ćemo večeras ostati kod kuće zbog kiše.

Postoji literally means there exists or there is. In this sentence, Postoji mogućnost... means There is a possibility...

This is a very common Croatian way to express possibility in a slightly more formal or neutral way.

• Postoji mogućnost da... = There is a possibility that...
• A less formal alternative might be Možda ćemo... = Maybe we will...

So postoji is not about physical existence only; it is also used for abstract things like chances, options, and possibilities.

Mogućnost is a feminine noun meaning possibility.

Here it is in the nominative singular, because it is the subject of postoji:

• Postoji mogućnost. = A possibility exists.

You are not seeing an ending change here because many feminine nouns ending in -ost have the same form in nominative singular.

Examples:

• mogućnost = possibility
• budućnost = future
• vrijednost = value

These nouns are very common in Croatian.

After nouns or expressions like mogućnost, Croatian often uses da + a finite verb clause to express that...

So:

• Postoji mogućnost da ćemo ostati kod kuće. = There is a possibility that we will stay home.

This is a normal structure in Croatian.

A learner may expect something more like an infinitive, but Croatian often prefers a da-clause in places where English might use to or a different structure.

Compare:

• Želim ići. = I want to go.
• Postoji mogućnost da ćemo ići. = There is a possibility that we will go.

So here da introduces the content of the possibility.

Ćemo ostati is the future tense: we will stay.

The sentence is talking about a possible event in the future, specifically this evening, so future tense is natural:

• ćemo ostati = we will stay

Croatian often uses future tense after da in this kind of sentence when the meaning is clearly future.

You may also encounter other structures in Croatian depending on style, dialect, or level of certainty, but da ćemo ostati is perfectly standard here.

Ostati means to stay, to remain, or to end up staying.

In ćemo ostati, the verb appears in the infinitive because Croatian future tense is formed with:

• a short form of htjeti (ću, ćeš, će, ćemo, ćete, će)
• • the infinitive

So:

• ja ću ostati = I will stay
• mi ćemo ostati = we will stay

A useful detail: ostati is usually perfective, which fits well when talking about a single complete event or decision, such as staying home tonight.

Its imperfective partner is usually ostajati, which would be used more for repeated or ongoing staying in some contexts.

Večeras means tonight or this evening.

It is an adverb of time, so it tells you when something may happen.

Compare:

• večer = evening
• večeras = tonight / this evening

Examples:

• Lijepa je večer. = It is a nice evening.
• Idemo van večeras. = We are going out tonight.

So in your sentence, večeras is not a noun; it is an adverb.

Kod kuće is a very common expression meaning at home.

Literally:

• kod often means something like at or by
• kuće is the genitive singular of kuća = house

So word-for-word it looks like at the house/home, but as a set phrase it simply means at home.

Examples:

• Ostajem kod kuće. = I am staying home.
• Jesi li kod kuće? = Are you at home?

A learner may also hear doma, which can also mean at home / home, depending on region and style. Both are common, but kod kuće is extremely standard.

The preposition zbog means because of.

After zbog, Croatian uses the genitive case.

So:

• kiša = rain
• kiše = genitive singular

That is why the sentence has:

• zbog kiše = because of the rain / because of rain

More examples:

• zbog vremena = because of the weather
• zbog posla = because of work
• zbog tebe = because of you

So this is a very useful pattern to remember:

• zbog + genitive

Yes. Croatian word order is more flexible than English word order, although some versions sound more natural than others depending on emphasis.

The original sentence is neutral and natural:

• Postoji mogućnost da ćemo večeras ostati kod kuće zbog kiše.

You could also say:

• Zbog kiše postoji mogućnost da ćemo večeras ostati kod kuće.
  • This puts more emphasis on because of the rain.
• Postoji mogućnost da ćemo zbog kiše večeras ostati kod kuće.
  • Also possible, with slightly different focus.

Croatian often moves phrases around to highlight new or important information.

No, Postoji mogućnost ostati kod kuće does not sound natural in standard Croatian.

After mogućnost, Croatian normally wants a fuller construction, for example:

• Postoji mogućnost da ćemo ostati kod kuće.
• Postoji mogućnost ostanka kod kuće.

The second version uses a noun:

• ostanka = of staying

But that version is more formal or abstract.

For everyday use, the da-clause is much more natural:

• Postoji mogućnost da...

The most direct negation is:

• Ne postoji mogućnost da ćemo večeras ostati kod kuće zbog kiše.

This means:

• There is no possibility that we will stay home tonight because of the rain.

You could also negate the second clause instead, depending on meaning:

• Postoji mogućnost da večeras nećemo ostati kod kuće zbog kiše.

That would mean:

• There is a possibility that we will not stay home tonight because of the rain.

So the place of the negation changes the meaning:

• Ne postoji mogućnost... = the possibility does not exist
• ...da nećemo ostati... = the possible event is negative

Yes, in many situations you could say:

• Možda ćemo večeras ostati kod kuće zbog kiše.

This means:

• Maybe we’ll stay home tonight because of the rain.

The difference is mainly in style:

• Postoji mogućnost da... sounds a bit more formal, careful, or analytical.
• Možda... sounds simpler and more conversational.

Both are correct, but they are not identical in tone.

Croatian has no articles like a, an, or the.

So nouns like mogućnost, kuće, and kiše do not automatically show definiteness the way English does. You understand it from context.

For example:

• zbog kiše can mean because of rain or because of the rain
• kod kuće simply means at home

This is something English speakers have to get used to: Croatian usually leaves this information to context instead of using articles.