Štene je cijelo jutro trčalo po hodniku, ali je mače ostalo mirno na tepihu.

Because štene and mače are grammatically neuter singular nouns in Croatian.

Even though they refer to animals, words like štene (puppy) and mače (kitten) are neuter. In the past tense, the main participle agrees with the subject in gender and number:

• masculine singular: trčao, ostao
• feminine singular: trčala, ostala
• neuter singular: trčalo, ostalo

So:

• Štene je trčalo
• Mače je ostalo

This is very common with names for young animals.

Je is the 3rd person singular present form of biti (to be), used as an auxiliary to form the past tense.

Croatian often forms the past like this:

• subject + auxiliary + past participle

So:

• Štene je trčalo = The puppy ran / was running
• Mače je ostalo = The kitten stayed / remained

The auxiliary agrees with the subject in person and number, while the participle agrees in gender and number.

It is repeated because there are really two separate clauses, each with its own verb phrase:

• Štene je cijelo jutro trčalo po hodniku
• ali je mače ostalo mirno na tepihu

Each clause normally needs its own auxiliary in the past tense.

In everyday speech, people may sometimes omit repeated elements if the meaning is obvious, but in a standard sentence like this, keeping both auxiliaries is natural and correct.

This has to do with clitic position in Croatian.

The auxiliary je is a clitic, and clitics usually come in the second position of their clause.

So after ali (but), it is very natural to place je immediately after it:

• ali je mače ostalo mirno

This may feel unusual to an English speaker, but it is normal Croatian word order.

You may also hear slightly different word orders in real usage, but ali je mače ostalo is very standard.

Cijelo jutro is in the accusative, and here it expresses duration of time: all morning.

Croatian often uses the accusative without a preposition to show how long something lasts:

• cijeli dan = all day
• cijelu noć = all night
• cijelo jutro = all morning

Since jutro is a neuter noun, the accusative singular form is the same as the nominative:

• nominative: jutro
• accusative: jutro

And cijelo matches it in neuter singular.

Here po hodniku means something like around the hallway, along the hallway, or throughout the hallway area.

The preposition po commonly takes the locative case, which is why hodnik becomes hodniku:

• nominative: hodnik
• locative: hodniku

So:

• po hodniku = in/around/along the hallway

This is a very common use of po when talking about movement over an area or within a space.

Because na can take different cases depending on whether there is movement toward a place or location in a place.

Here the kitten is already staying in one place, so Croatian uses the locative:

• na tepihu = on the carpet

Compare:

• skočiti na tepih = to jump onto the carpet
  
  • motion toward a destination → accusative
• biti na tepihu = to be on the carpet
  
  • location → locative

Since ostalo means stayed/remained, a location meaning is needed, so na tepihu is correct.

Here mirno is best understood as an adjective in neuter singular, agreeing with mače, not as an adverb.

It means still, calm, or quiet as a description of the kitten’s state:

• mače je ostalo mirno = the kitten remained still/calm

Because mače is neuter singular, the adjective is also neuter singular:

• masculine: miran
• feminine: mirna
• neuter: mirno

So this is about what the kitten was like, not how it performed the action.

They come from verbs with different aspectual behavior:

• trčati = to run → typically imperfective
• ostati = to stay/remain → typically perfective

In this sentence:

• trčalo presents an ongoing or repeated activity over a stretch of time: all morning
• ostalo presents the result/state of remaining still

This combination is very natural:

• one animal was busy moving around
• the other stayed in a fixed state

English learners often notice that Croatian aspect is not always translated directly. Here the sentence is contrasting an ongoing activity with a completed or established state.

Croatian normally has no articles like English a/an/the.

So:

• štene can mean a puppy or the puppy
• mače can mean a kitten or the kitten

The exact meaning depends on context. In this sentence, English would naturally use the puppy and the kitten, but Croatian does not need separate words for that.

A rough English-friendly guide:

• Štene ≈ SHTEH-neh
• cijelo ≈ tsyEH-loh or tsee-EH-loh
• trčalo ≈ TRR-cha-loh
• hodniku ≈ HOD-nee-koo
• mače ≈ MAH-cheh
• tepihu ≈ TEH-pee-hoo

A few useful sound notes:

• š sounds like sh
• č sounds like ch in church
• c sounds like ts
• r can be rolled or tapped
• stress is not usually marked in normal writing, so learners typically pick it up by listening

Yes. That is a very natural translation.

Croatian past tense does not map perfectly onto English simple past vs past continuous. Because of the verb trčati and the time phrase cijelo jutro, English often prefers:

• was running around the hallway all morning

while ostalo mirno naturally becomes:

• stayed still
• remained still

So several English translations are possible, depending on style:

• The puppy ran around the hallway all morning, but the kitten stayed still on the carpet.
• The puppy was running around the hallway all morning, but the kitten remained still on the carpet.