Selo je udaljeno jednu milju.

Because selo is a neuter singular noun.

The word udaljen behaves like an adjective here, so it has to agree with selo in gender and number:

• udaljen = masculine singular
• udaljena = feminine singular
• udaljeno = neuter singular

So:

• Grad je udaljen... = The town/city is ... away
• Kuća je udaljena... = The house is ... away
• Selo je udaljeno... = The village is ... away

Since selo is neuter, udaljeno is the correct form.

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

So je udaljeno literally means something like is distant / is situated at a distance / is removed.

In natural English, the whole sentence is usually translated as:

• The village is one mile away.

So the structure is:

• Selo = the village
• je = is
• udaljeno = distant / away
• jednu milju = one mile

Because milja is a feminine noun, and the numeral jedan has to agree with it.

Here are the singular forms of one:

• jedan = masculine
• jedna = feminine
• jedno = neuter

But in this sentence, the phrase is in the accusative, not the nominative, so feminine jedna becomes jednu:

• nominative: jedna milja
• accusative: jednu milju

So jednu milju is correct.

Croatian often uses the accusative to express extent, distance, or duration.

So in a sentence like this, the distance is treated as a kind of measure:

• jednu milju = one mile
• dva kilometra = two kilometers
• tri sata = three hours

This is similar to how English says:

• It is one mile away
• He waited three hours

In Croatian, this measured amount often appears in the accusative.

In this sentence, it works like an adjective.

It comes from the verb family related to udaljiti / udaljavati, but in sentences like this it is commonly used as an adjectival form meaning:

• distant
• away
• located at a distance

So Selo je udaljeno jednu milju is structurally similar to:

• Selo je veliko. = The village is big.
• Selo je udaljeno jednu milju. = The village is one mile away.

In both cases, je + adjective forms the predicate.

Yes, you often can.

Both are understandable:

• Selo je udaljeno jednu milju.
• Selo je udaljeno milju.

Including jednu can make the phrase sound a bit more explicit or careful, similar to English one mile instead of just a mile.

In everyday usage, speakers may use either form depending on style and context.

Because Croatian does not always need to state that if the reference point is already understood from context.

So Selo je udaljeno jednu milju simply means:

• The village is one mile away.

If you want to specify the reference point, you can add it:

• Selo je udaljeno jednu milju od grada. = The village is one mile from the town.
• Selo je udaljeno jednu milju odavde. = The village is one mile from here.

The basic sentence leaves that information unstated.

Sometimes daleko can express a similar idea, but it is not used in exactly the same way.

• Selo je daleko. = The village is far away.
• Selo je udaljeno jednu milju. = The village is one mile away.

With a specific measured distance, udaljeno is a very natural choice.
Daleko is more about being far, not usually about a precise distance.

So for one mile away, udaljeno is the better fit.

No, Croatian word order is fairly flexible, although some versions sound more neutral than others.

The most neutral order here is:

• Selo je udaljeno jednu milju.

But other orders are possible depending on emphasis, for example:

• Jednu milju je selo udaljeno.
• Udaljeno je jednu milju selo.

These are less neutral and would usually be used only in special contexts. For learners, the original order is the safest and most natural.

It can mean either, depending on context.

Croatian has no articles like a or the, so selo by itself can mean:

• a village
• the village

In this sentence, English would often translate it as the village if both speaker and listener already know which village is meant. But grammatically, Croatian does not mark that difference with an article.