Glavni projekt je spreman.

Croatian normally has no articles, so there is no separate word for the or a/an.

That means a noun like projekt can mean:

• project
• the project
• sometimes even a project

You understand which one is meant from context. In this sentence, English naturally uses the: The main project is ready.

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

So:

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

In Glavni projekt je spreman, je simply means is.

Because glavni has to agree with projekt.

Projekt is:

• masculine
• singular
• nominative here, because it is the subject

So the adjective must also be masculine singular nominative:

• masculine: glavni
• feminine: glavna
• neuter: glavno

Examples:

• glavni projekt = main project
• glavna ideja = main idea
• glavno pitanje = main question

Because spreman is a predicate adjective and it also agrees with the subject, projekt.

So even though it comes after je, it still matches projekt in gender and number:

• projekt je spreman = the project is ready
• ideja je spremna = the idea is ready
• pitanje je spremno = the question is ready

This is very common in Croatian: adjectives after biti still agree with the subject.

Yes. In this sentence, spreman is nominative masculine singular.

That may feel unusual if you know some other Slavic languages, because some of them use different patterns after to be. In Croatian, with a sentence like this, the adjective is normally in the nominative:

• Projekt je spreman.
• Kuća je velika.
• Plan je dobar.

So both glavni and spreman match the subject in nominative form.

A good clue is its dictionary form and adjective agreement.

In this sentence:

• glavni is masculine singular
• spreman is masculine singular

That tells you projekt is masculine too.

Also, many Croatian masculine nouns have no ending or end in a consonant in the nominative singular, and projekt fits that pattern.

Yes, Croatian word order is more flexible than English, but the meaning or emphasis can shift.

The neutral order here is:

• Glavni projekt je spreman.

You could also say:

• Projekt je spreman. = The project is ready.
• Spreman je glavni projekt. = possible, but marked; it sounds like you are emphasizing ready
• Projekt je glavni. = this does not mean the same thing; it means The project is the main one

So word order can change, but not every rearrangement keeps the same meaning or sounds equally natural.

Not only. Glavni can also mean things like:

• main
• principal
• chief
• leading

The best English choice depends on context.

For example:

• glavni grad = capital city
• glavni ulaz = main entrance
• glavni problem = main problem

In your sentence, main is the most natural translation.

Not always. Spreman can mean:

• ready
• prepared
• willing in some contexts

Examples:

• Projekt je spreman. = The project is ready.
• Spreman sam za ispit. = I am prepared/ready for the exam.
• Spreman sam pomoći. = I am willing/ready to help.

So the core idea is readiness or preparedness.

In Croatian, j is pronounced like English y in yes.

So projekt is roughly:

• pro-yekt

And:

• je sounds roughly like ye

That means:

• projekt je sounds approximately like pro-yekt ye

This is one of the most important pronunciation differences for English speakers.

Yes, in ordinary neutral Croatian, adjectives usually come before the noun:

• glavni projekt
• velika kuća
• dobar plan

Putting the adjective after the noun is uncommon in normal everyday prose and usually sounds poetic, formal, or stylistically marked. So glavni projekt is the expected order.

Grammatically, Croatian itself does not mark that distinction with an article, so in isolation the sentence does not explicitly say the or a.

However, in real usage, glavni projekt usually sounds like the main project, because main often implies a specific one. So in most contexts, The main project is ready is the best English translation.