Moje boravište vrijedi do ljeta.

Because moje has to agree with boravište in gender, number, and case.

• boravište is neuter singular
• the sentence uses it in the nominative singular because it is the subject
• the possessive adjective moj therefore becomes moje

So:

• moj = masculine
• moja = feminine
• moje = neuter

Since boravište is neuter, moje boravište is the correct form.

It is in the nominative singular.

In this sentence, boravište is the thing that vrijedi — in other words, it is the subject of the sentence. Subjects are normally in the nominative case in Croatian.

So the basic structure is:

• Moje boravište = the subject
• vrijedi = the verb
• do ljeta = a time expression meaning how long something is valid

Boravište usually means temporary residence or place of stay/residence, especially in an administrative or legal sense.

A useful contrast is:

• prebivalište = permanent residence
• boravište = temporary residence

So boravište is not just any random place where you are staying for a moment; it often has an official, registered meaning.

Not exactly.

This is an important distinction:

• boravište = residence / temporary residence / registered place of stay
• boravišna dozvola or dozvola boravka = residence permit

So if the intended meaning is My residence permit is valid until summer, a native speaker would often say something like:

• Moja boravišna dozvola vrijedi do ljeta.

The original sentence is grammatically fine, but depending on context, boravište may sound more like temporary residence status/address than the physical permit document.

Here vrijedi means is valid.

The verb is vrijediti, which can mean different things depending on context, such as:

• to be worth
• to be valid
• to apply

In this sentence, the meaning is clearly to be valid.

So:

• Ovo vrijedi deset eura. = This is worth ten euros.
• Propusnica vrijedi do petka. = The pass is valid until Friday.

In your sentence, vrijedi is the 3rd person singular present tense form.

Because the preposition do requires the genitive case.

The noun ljeto is a neuter noun, and its genitive singular form is ljeta.

So:

• nominative: ljeto
• genitive: ljeta

That is why you get:

• do ljeta = until summer

This is a very common pattern in Croatian:

• do kraja = until the end
• do jutra = until morning
• do grada = to the town / up to the town

In this sentence, it most naturally means until summer.

With a verb like vrijediti meaning to be valid, do ljeta tells you the end point of validity. So the idea is that it remains valid up to summer.

Sometimes in other contexts do can be translated more like by, especially when talking about deadlines, but here until summer is the best fit.

Because the sentence describes a current state that continues up to a point in the future.

The meaning is basically:

• It is valid now
• and that validity continues until summer

Croatian, like English, often uses the present tense for this kind of statement.

Compare the English sentence:

• My permit is valid until summer.

That is also present tense, even though summer is in the future.

Yes. Croatian word order is more flexible than English word order, because case endings carry a lot of grammatical information.

The version you have:

• Moje boravište vrijedi do ljeta.

is a neutral, straightforward order.

Other possible orders are:

• Do ljeta vrijedi moje boravište.
• Boravište mi vrijedi do ljeta.

These can sound more marked, more contextual, or more natural depending on what is being emphasized.

For example:

• Boravište mi vrijedi do ljeta. puts the possession into the dative clitic mi = to me / my, which is often very natural in everyday speech.

It depends on the intended meaning.

If you really mean my temporary residence / residence registration is valid until summer, then the sentence is understandable and can work.

But if you mean my residence permit is valid until summer, many native speakers would more naturally say:

• Moja boravišna dozvola vrijedi do ljeta.
• Dozvola boravka mi vrijedi do ljeta.

So the sentence is useful for grammar, but the most natural vocabulary choice depends on whether you mean:

• the residence status/address (boravište), or
• the permit/document (boravišna dozvola, dozvola boravka)