Gradilište je otvoreno.

Because gradilište is a neuter singular noun in Croatian.

The adjective/predicative form has to agree with the noun:

• otvoren = masculine singular
• otvorena = feminine singular
• otvoreno = neuter singular

So:

• Gradilište je otvoreno. = The construction site is open.

A few comparison examples:

• Trgovina je otvorena. = The shop is open. (trgovina is feminine)
• Ured je otvoren. = The office is open. (ured is masculine)
• Gradilište je otvoreno. = The construction site is open. (gradilište is neuter)

A very common clue is the ending -e or -o in the dictionary form of the noun. Many Croatian neuter nouns end that way.

So gradilište is neuter singular.

Also, the ending -ište often forms neuter nouns, especially for places connected with an action or activity. That is why gradilište behaves as a neuter noun.

Gradilište means construction site or building site.

It comes from the verb graditi, meaning to build.

So the idea is:

• graditi = to build
• gradilište = a place where building/construction is happening

For an English speaker, construction site is usually the most natural translation.

Je is the 3rd person singular present tense of the verb biti, meaning to be.

So:

• ja sam = I am
• ti si = you are
• on/ona/ono je = he/she/it is

In this sentence:

• Gradilište je otvoreno. literally = Construction site is open.

Croatian usually does use je in this kind of sentence, unlike Russian-style zero-copula structures.

Because Croatian usually does not need a subject pronoun when the subject is already expressed or understood.

Here, the subject is explicitly there:

• Gradilište = the construction site

So there is no need to add a separate word for it.

Croatian often leaves out subject pronouns unless they are needed for emphasis or contrast.

In this sentence, otvoreno functions as a predicate adjective: it describes the state of the subject after the verb je.

So structurally:

• Gradilište = subject
• je = is
• otvoreno = open

Historically and grammatically, forms like otvoren / otvorena / otvoreno are connected with the past passive participle, but for a learner it is usually most useful to understand otvoreno here simply as the agreeing form meaning open.

In this sentence, it normally means open, describing a current state.

So:

• Gradilište je otvoreno. = The construction site is open.

Depending on context, forms like this can sometimes feel close to has been opened or is opened, but in everyday usage this sentence is most naturally understood as a state, not as an action.

English usually translates it as open, not opened.

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

The most neutral version is:

• Gradilište je otvoreno.

But you may also hear:

• Otvoreno je gradilište.
• Je li gradilište otvoreno? = Is the construction site open?

Different word orders can change emphasis, style, or information structure, but the basic meaning stays the same.

For a learner, Gradilište je otvoreno is the safest and most neutral order.

A helpful approximate pronunciation is:

gra-di-li-shte

A few details:

• g is always a hard g, like in go
• r is rolled or tapped
• š sounds like sh in shoe
• te is pronounced clearly, not reduced like in English

So gradilište sounds roughly like gra-dee-lee-shte.

Š is pronounced like sh in English ship or shoe.

So:

• š = sh

That means:

• gradilište ends with a sound like -shte

Croatian spelling is quite regular, so once you learn a letter, it is usually pronounced the same way every time.

Croatian does not have articles like English a/an and the.

So:

• gradilište can mean a construction site or the construction site
• the exact meaning depends on context

In this sentence, English often uses the:

• The construction site is open.

But Croatian does not need a separate word for that.

Yes. The verb je is present tense, so the sentence is in the present.

It describes the current state:

• Gradilište je otvoreno. = The construction site is open.

It is not a past-tense sentence, even though otvoreno may look like a participle-related form.

Sometimes context can allow that interpretation, but on its own the sentence usually means it is open.

If someone wanted to strongly emphasize the event of opening, Croatian would often use a fuller expression, depending on the context.

So for a learner, the safest understanding is:

• Gradilište je otvoreno. = The construction site is open.

Yes, it could be natural, especially if the intended meaning is that the site is open, accessible, or operating.

Croatian signs often use short, direct wording. In some situations, though, a sign might more commonly use a noun phrase or another fixed expression depending on what exactly is meant.

Still, grammatically and naturally, Gradilište je otvoreno. is perfectly fine.