U kutu štale bilo je suho sijeno za konje i krave.

Because u means in here, and it expresses location, not movement.

In Croatian:

• u + locative = in/at somewhere
• u + accusative = into somewhere

So:

• u kutu = in the corner / at the corner
• if there were movement, you could have something like staviti u kut = to put into the corner

Here nothing is moving, so kutu is in the locative singular.

Štale is genitive singular of štala (barn, stable).

In u kutu štale, the word štale means of the barn:

• kut = corner
• kutu = in the corner
• štale = of the barn

So the whole phrase means in the corner of the barn.

This is a very common Croatian pattern: one noun followed by another noun in the genitive to show possession or a part-whole relationship.

Because the sentence does not say simply in the barn. It says in the corner of the barn.

Compare:

• u štali = in the barn
• u kutu štale = in the corner of the barn

So štali would be locative after u, but here u only governs kutu. The word štale depends on kutu, not directly on u.

Bilo je is the past tense of biti (to be), and here it means there was.

So:

• bilo je = there was / was

In this sentence, the structure is like:

• U kutu štale bilo je suho sijeno...
• In the corner of the barn there was dry hay...

The form bilo is neuter singular, which matches sijeno, because sijeno is a neuter singular noun.

Because adjectives in Croatian must agree with the noun in:

• gender
• number
• case

Sijeno is:

• neuter
• singular
• here in the basic subject form

So the adjective must also be neuter singular:

• suho = dry (neuter singular)
• sijeno = hay (neuter singular)

That is why it is suho sijeno, not suha or suh.

Yes, sijeno is singular here, but it is a mass noun.

Just like English hay, it usually refers to a substance rather than separate countable items. So Croatian normally uses the singular:

• sijeno = hay

This is similar to English:

• There was hay in the barn not
• There were hays in the barn

Here za means for, and in this meaning it takes the accusative.

So:

• za konje = for horses
• za krave = for cows

Both nouns are in the accusative plural:

• konji → konje
• krave → krave (same form as nominative plural here)

So za konje i krave means that the hay is intended for horses and cows.

It describes the hay.

The meaning is:

• dry hay for horses and cows

It does not mean that the horses and cows were in the corner.

If you wanted to say that, Croatian would use a different sentence, for example:

• U kutu štale bili su konji i krave.
• There were horses and cows in the corner of the barn.

So in the original sentence, za konje i krave attaches naturally to sijeno.

Because Croatian has no articles.

English says:

• in the corner of the barn
• there was dry hay

Croatian simply says:

• u kutu štale
• bilo je suho sijeno

Croatian usually shows definiteness from context, not from separate words like the or a.

Yes. Croatian word order is fairly flexible.

This version:

• U kutu štale bilo je suho sijeno za konje i krave.

puts the location first, which sounds natural because it sets the scene: In the corner of the barn...

You could rearrange parts of the sentence, but the original order is a normal, natural way to present new information. In many cases, Croatian word order helps show focus and emphasis, not just grammar.

Croatian has a strong tendency for short unstressed words, called clitics, to appear near the second position in the sentence or clause.

The word je is one of these clitics.

So in:

• U kutu štale bilo je suho sijeno...

the clitic je comes after the first larger unit of the clause, not necessarily after the first single word.

This is a normal Croatian pattern and something learners see very often with forms like:

• je
• su
• sam
• se
• ga
• mu

So the placement of je here is not random; it follows a common clitic-order rule.