Kad je mače zaspalo, moja nećakinja je pokraj njega stavila malu deku i rekla da je štene preglasno.

Because the sentence contains two different functions of je:

1. Kad je mače zaspalo
   Here je is an auxiliary verb used to form the past tense.

2. ... rekla da je štene preglasno
   Here je means is and links the subject to an adjective, like the puppy is too loud.

So even though both forms look the same, they do different jobs.

These are all in the Croatian past tense, often called the perfect.

It is formed with:

• the present tense of biti (to be)
• plus the past participle

Examples from the sentence:

• je zaspalo = fell asleep / has fallen asleep
• je stavila = put
• je rekla = said

The participle changes to match the gender and number of the subject:

• zaspalo → neuter singular, matching mače
• stavila → feminine singular, matching moja nećakinja
• rekla → feminine singular, again matching moja nećakinja

Because mače is a neuter noun in Croatian.

That means the past participle must also be neuter:

• masculine: zaspao
• feminine: zaspala
• neuter: zaspalo

So:

• mače je zaspalo = correct

This is very common with nouns like:

• mače = kitten
• štene = puppy
• dijete = child

Even if the animal is biologically male or female, the grammar follows the noun’s grammatical gender unless you use a specifically gendered noun.

For the same reason: štene is also a neuter noun.

The adjective must agree with it:

• masculine: preglasan
• feminine: preglasna
• neuter: preglasno

So:

• štene je preglasno = the puppy is too loud

Because nećakinja is a feminine noun, and the possessive adjective must agree with it.

So:

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

Since nećakinja means niece, it is feminine:

• moja nećakinja = my niece

Njega is in the genitive case.

The preposition pokraj usually takes the genitive, and it means beside, next to, or by.

So:

• pokraj njega = beside him/it

Here njega refers to mače. In English we would probably say beside it, but Croatian often uses the same pronoun form regardless of whether English would choose him or it, depending on context and the grammatical pattern.

This is a very common learner question.

Even though mače is grammatically neuter, when referring to an animal or living being, Croatian often uses personal pronoun forms like njega.

So the sentence says:

• pokraj njega = beside it / beside him

In real usage, this sounds natural for an animal. Croatian does not always match English’s strict it for animals.

Because deku is in the accusative case, since it is the direct object of stavila (put).

The basic form is:

• mala deka = a small blanket

But after a transitive verb like staviti, the direct object goes into the accusative:

• malu deku

Both the adjective and noun change because they must agree:

• nominative: mala deka
• accusative: malu deku

Pokraj means beside, next to, or by.

In many contexts, you could also hear:

• kraj njega
• pored njega

All can mean something like next to him/it.

There can be small stylistic or regional preferences, but in this sentence pokraj njega is perfectly natural.

Because da introduces a subordinate clause, very often corresponding to English that.

So:

• rekla da je štene preglasno
  = said that the puppy was too loud

In English, that is often optional:

• She said the puppy was too loud.

In Croatian, da is normally used here.

This is because Croatian often uses the present tense after rekla da... when reporting a statement that was true at that time.

So:

• rekla da je štene preglasno
  literally: she said that the puppy is too loud

But in natural English translation, this often becomes:

• she said that the puppy was too loud

This kind of tense matching does not work exactly the same way in Croatian and English. Croatian does not always shift the tense backward the way English often does in reported speech.

Preglasno means too loud.

It is built from:

• glasan = loud
• prefix pre- = too, overly

So:

• preglasan / preglasna / preglasno = too loud

Because it agrees with štene (neuter), the form here is preglasno.

Yes, mostly.

Both mean when.

• kad is very common in everyday speech and writing
• kada can sound a bit fuller or slightly more formal, depending on context

So you could also say:

• Kada je mače zaspalo...

Both are correct.

Croatian word order is fairly flexible, but not completely free.

This sentence uses a very natural order:

• Kad je mače zaspalo, moja nećakinja je pokraj njega stavila malu deku...

You could rearrange parts for emphasis, for example:

• Kad je mače zaspalo, moja nećakinja stavila je malu deku pokraj njega.

That is also correct.

A very important point is that short unstressed words like je often behave as clitics, and they tend to appear in or near the second position of their clause. That is one reason Croatian word order can feel unusual to English speakers.

This is because je is a clitic.

Croatian clitics usually go in the second position in a clause, not necessarily right next to the main verb in the way English auxiliary verbs often do.

So:

• moja nećakinja je stavila = normal
• moja nećakinja stavila je = also possible in some word orders and styles

Clitic placement is one of the trickier parts of Croatian syntax, and learners usually need time to get used to it.

Yes.

Both of these are natural:

• stavila malu deku pokraj njega
• pokraj njega stavila malu deku

The difference is mostly one of emphasis or rhythm.

Placing pokraj njega earlier may slightly highlight the location. Croatian often allows this kind of movement more freely than English does.

Not exactly.

Zaspati means to fall asleep.

That is different from:

• spavati = to sleep

So:

• mače je zaspalo = the kitten fell asleep
• mače je spavalo = the kitten was sleeping / slept

This distinction is important because Croatian often uses different verbs for entering a state and being in that state.