Staklo na prozoru je mokro od kiše.

Because staklo means glass, while prozor means window.

So:

• staklo = the glass pane
• prozor = the whole window

In this sentence, Staklo na prozoru means the glass on/in the window, not the whole window frame.

A learner might translate it more naturally into English as The window glass is wet from the rain.

Because na changes case depending on meaning.

Here it expresses a location: the glass is on / in the window. For location, na takes the locative case.

• na prozoru = on/in the window → location

If there were movement toward something, Croatian would normally use the accusative:

• na prozor = onto the window

So:

• Staklo na prozoru... = the glass located on/in the window
• movement would require a different meaning

Prozoru is locative singular of prozor.

The basic form is:

• prozor = window

After na when it means location, the noun goes into the locative:

• na prozoru = on/in the window

The ending -u is a normal locative singular ending for many masculine nouns.

So the pattern is:

• nominative: prozor
• locative: prozoru

Because adjectives in Croatian must agree with the noun in gender, number, and case.

The noun here is staklo, which is:

• neuter
• singular
• nominative

So the adjective must also be neuter singular nominative:

• mokro = wet

Compare:

• mokar = masculine singular
• mokra = feminine singular
• mokro = neuter singular

Since staklo is neuter, mokro is the correct form.

Je is the 3rd person singular present of biti = to be.

So:

• je mokro = is wet

The structure is very similar to English:

• Staklo ... je mokro.
• The glass ... is wet.

In standard Croatian, this verb is normally used in this kind of sentence with a predicate adjective.

Literally, od kiše means from the rain.

In natural English, that usually becomes:

• wet from the rain
• wet because of the rain
• rain-wet

So in this sentence, od kiše explains the cause of the wetness.

Croatian often uses od + genitive to show that something is caused by or comes from something.

Because the preposition od requires the genitive case.

The basic form is:

• kiša = rain

After od, it changes to genitive singular:

• od kiše = from the rain

So the pattern is:

• nominative: kiša
• genitive: kiše

This is one of the most common things Croatian learners need to notice: prepositions often force a specific case.

It can correspond to either in English, depending on context.

In this sentence, English would usually say:

• the glass in the window
• or the glass on the window

But the most natural interpretation is the window glass.

Croatian na does not always match English on perfectly word-for-word. Very often you have to translate the whole phrase naturally rather than mechanically.

Because Croatian does not have articles like English a and the.

So:

• staklo can mean glass, the glass, or a glass, depending on context
• prozor can mean window, the window, or a window

In this sentence, the context makes it natural to understand the glass on the window or the window glass.

Not completely. Croatian word order is more flexible than English because cases show grammatical relationships.

The sentence:

• Staklo na prozoru je mokro od kiše.

is a normal, natural order.

But Croatian could rearrange parts for emphasis, for example:

• Staklo je na prozoru mokro od kiše.
• Od kiše je staklo na prozoru mokro.

These alternatives may sound more marked or emphasize different information. The original version is the most neutral and straightforward for a learner.

Not really, because the sentence specifically says staklo.

That points to the glass part of the window. If you wanted to say the whole window is wet, you would more likely say:

• Prozor je mokar od kiše. = The window is wet from the rain.

So the choice of staklo is meaningful: it narrows the focus to the pane of glass.