Na balkonu nema dovoljno štipaljki za sve ručnike.

Because na balkonu means on the balcony in the sense of location.

With na, Croatian often uses:

• locative for where something is
• accusative for where something is going

So:

• na balkonu = on the balcony / at the balcony
• na balkon = onto the balcony

In this sentence, the clothespins are already there, so Croatian uses the locative: balkonu.

Nema is the negative form of ima in the sense of there is / there are / has.

• ima = there is / there are
• nema = there is not / there are not

So:

• Na balkonu ima štipaljki. = There are clothespins on the balcony.
• Na balkonu nema štipaljki. = There are no clothespins on the balcony.

In your sentence, nema dovoljno... means there are not enough...

Because nema normally requires the genitive.

The base noun is:

• štipaljka = a clothespin / peg

Its plural forms include:

• štipaljke = nominative plural
• štipaljki = genitive plural

After nema, Croatian uses the genitive, so:

• nema štipaljki = there are no clothespins

That is why you see štipaljki.

Dovoljno means enough.

In Croatian, dovoljno is often followed by a noun in the genitive:

• dovoljno vremena = enough time
• dovoljno novca = enough money
• dovoljno štipaljki = enough clothespins

So in nema dovoljno štipaljki, both the idea of absence and the word dovoljno fit naturally with the genitive.

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

The noun is:

• ručnik = towel

Its accusative plural is:

• ručnike

And sve agrees with it:

• svi = all
• sve ručnike = all the towels

So:

• za sve ručnike = for all the towels

Because the phrase depends on za, which requires the accusative here.

Compare:

• za sve ručnike = for all the towels
• bez svih ručnika = without all the towels

In the first one, za triggers the accusative, so you get:

• sve
  • ručnike

If the grammar required genitive, then you would see forms like svih ručnika.

Here is the breakdown:

• Na — preposition
• balkonu — locative singular of balkon
• nema — negative form of ima
• dovoljno — indeclinable word meaning enough
• štipaljki — genitive plural of štipaljka
• za — preposition
• sve — accusative plural form agreeing with ručnike
• ručnike — accusative plural of ručnik

So the sentence combines:

• a location phrase: na balkonu
• a there isn’t enough structure: nema dovoljno štipaljki
• a for + accusative phrase: za sve ručnike

Yes, Croatian word order is fairly flexible, though some versions sound more natural than others.

The neutral version is:

• Na balkonu nema dovoljno štipaljki za sve ručnike.

You could also hear:

• Nema dovoljno štipaljki na balkonu za sve ručnike.
• Za sve ručnike nema dovoljno štipaljki na balkonu.

These alternatives may change the focus or emphasis, but the basic meaning stays the same.

The original sentence sounds natural and neutral.

Yes, štipaljka is a common everyday word for a clothespin, especially in this context.

Depending on region, people may also use other words, but štipaljka is widely understood and completely normal.

In this sentence:

• štipaljki = clothespins / pegs, in the genitive plural

A natural positive version would be:

• Na balkonu ima dovoljno štipaljki za sve ručnike.

That means:

• There are enough clothespins on the balcony for all the towels.

So the contrast is:

• ima dovoljno... = there are enough...
• nema dovoljno... = there are not enough...

Roughly, štipaljki sounds like:

• shti-PAL-yee-kee

A few pronunciation notes:

• š sounds like sh in shoe
• lj is a single Croatian sound, similar to the lli in some pronunciations of million, though not exactly the same
• stress is not usually marked in normal writing, so learners often just imitate native audio when possible

So štipaljki may feel tricky mostly because of ljk in the middle. Slow practice helps:

• šti-palj-ki

Yes. Croatian has no articles like a or the, so whether English uses towels, the towels, or sometimes even some towels depends on context.

Here, sve ručnike most naturally means:

• all the towels

because all towels in English sounds more general, while this Croatian sentence usually refers to a specific set of towels.

So even without an article in Croatian, English often needs one in translation.