Boca je izvana mokra.

Because mokra must agree with boca in gender, number, and case.

• boca is a feminine singular noun
• the adjective mokra is the feminine singular form of mokar (wet)

So:

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

Since boca is feminine, mokra is the correct form.

Je is the 3rd person singular present tense of biti (to be).

So it means is.

In Boca je izvana mokra, the structure is basically:

• Boca = the bottle
• je = is
• izvana = on the outside / externally
• mokra = wet

Croatian usually uses je in this kind of sentence, just like English uses is.

Izvana is an adverb. Here it means on the outside, from the outside, or externally, depending on context.

In this sentence, it tells you that the bottle is wet on its outer surface, not necessarily inside.

So izvana adds an important detail: the wetness is specifically external.

Not exactly.

• izvana = from the outside / on the outside / externally
• vani = outside, usually meaning location
• izvan = outside of, and it is normally used with a noun in the genitive

Examples:

• Boca je izvana mokra. = The bottle is wet on the outside.
• Djeca su vani. = The children are outside.
• Izvan kuće je hladno. = Outside the house it is cold.

So in your sentence, izvana is the natural choice because it describes the bottle’s outer side.

Croatian has no articles, so there is no direct equivalent of the or a/an.

That means boca can mean:

• a bottle
• the bottle

Which one is meant depends on the context.

So English needs an article, but Croatian does not.

Yes. Croatian word order is more flexible than English word order.

The sentence Boca je izvana mokra is natural, but you may also hear:

• Boca je mokra izvana.

Both are correct. The difference is mostly about focus or style.

• Boca je izvana mokra puts izvana earlier, so the outside aspect is introduced sooner.
• Boca je mokra izvana may sound a bit more like The bottle is wet, on the outside.

English is much stricter with word order than Croatian.

Yes, boca is a feminine noun.

A useful clue is that many Croatian nouns ending in -a are feminine, although there are exceptions elsewhere in the language.

Because boca is feminine, words connected to it often appear in feminine forms, like:

• mokra boca = wet bottle
• ova boca = this bottle
• ta boca = that bottle

It is in the nominative singular.

That is because boca is the subject of the sentence: the bottle is the thing being described.

The sentence is a simple subject + verb + description structure, so nominative is what you expect for boca here.

Not necessarily. It specifically says the bottle is wet izvana, meaning on the outside.

So the sentence focuses on the bottle’s outer surface. It does not say whether the inside is wet or dry.

If you wanted to talk about the inside, you would need different wording.

A rough pronunciation guide is:

BO-tsa yee EES-vah-nah MO-krah

A few key sounds:

• c in boca sounds like ts
• j in je sounds like English y
• r in mokra is a rolled or tapped r

So boca is not pronounced like English boca in Spanish-influenced words; in Croatian it is BO-tsa.

You could, but it would sound more marked and would usually be used for special emphasis.

The most neutral versions are:

• Boca je izvana mokra.
• Boca je mokra izvana.

If you move mokra to the front, you are strongly emphasizing wet. Croatian allows that, but it is not the most basic word order for a learner to start with.

In practical terms, it tells you in what respect the bottle is wet, so learners can think of it as modifying the description mokra.

It narrows the meaning:

• not just wet
• but wet on the outside

So even if you do not analyze the syntax very deeply, the useful takeaway is that izvana gives the location/aspect of the wetness.