Policajka je zaustavila auto na raskrižju jer vozač nije vidio pješake.

Policajka means policewoman or female police officer. It is a feminine noun.

That matters grammatically, because in Croatian the past participle agrees with the subject. So with policajka, you get zaustavila (feminine singular), not zaustavio (masculine singular).

Croatian commonly forms the past tense with:

• a form of biti (to be)
• plus a past participle

So:

• je = auxiliary verb
• zaustavila = past participle

Together, je zaustavila means stopped / has stopped in English-style meaning.

A few examples:

• On je zaustavio = He stopped
• Ona je zaustavila = She stopped
• Oni su zaustavili = They stopped

Also, je is a clitic, so it usually appears near the beginning of the clause, often in second position.

Because it agrees with the subject policajka, which is feminine singular.

In Croatian past participles change for gender and number:

• zaustavio = masculine singular
• zaustavila = feminine singular
• zaustavilo = neuter singular
• zaustavili = plural masculine/mixed
• zaustavile = plural feminine

So Policajka je zaustavila is grammatically matched.

Auto is the direct object of the verb zaustavila, so it is in the accusative singular.

But auto is a neuter noun, and for many neuter nouns the nominative and accusative singular look the same.

So:

• auto = nominative singular
• auto = accusative singular

That is why the form does not visibly change here.

Because na can take different cases depending on the meaning:

• na + locative = location (at/on)
• na + accusative = direction (onto/to)

Here the meaning is location: the car was stopped at the intersection, so Croatian uses locative:

• na raskrižju = at the intersection

The basic noun is raskrižje. Its locative singular is raskrižju.

Compare:

• Auto je na raskrižju. = The car is at the intersection.
• Vozi na raskrižje. = He is driving to the intersection.

Jer means because.

So:

• ...jer vozač nije vidio pješake = ...because the driver did not see the pedestrians

Yes, you could often also use zato što, which also means because:

• Policajka je zaustavila auto na raskrižju zato što vozač nije vidio pješake.

Both are natural. Jer is short and very common.

In Croatian, the negative form of je is nije.

So:

• je vidio = saw / has seen
• nije vidio = did not see / has not seen

You do not normally say ne je vidio.

This is a very common pattern:

• nije došao = he didn’t come
• nije rekla = she didn’t say
• nije vidio = he didn’t see

Because the subject of that clause is vozač (driver), which is masculine singular.

Again, the past participle agrees with the subject:

• vozač nije vidio = the male driver did not see
• vozačica nije vidjela = the female driver did not see

So vidio matches vozač.

Because pješake is the accusative plural form of pješak (pedestrian), and it is the direct object of vidio.

Relevant forms are:

• pješak = nominative singular
• pješaci = nominative plural
• pješake = accusative plural

So:

• vozač nije vidio pješake = the driver did not see the pedestrians

This is one of the forms English speakers often need to memorize, because Croatian marks the object with case endings.

Not as fixed as in English.

The given sentence has a very normal, neutral word order:

• Policajka je zaustavila auto na raskrižju jer vozač nije vidio pješake.

But Croatian allows some movement for emphasis or style, for example:

• Policajka je na raskrižju zaustavila auto...
• ...jer vozač pješake nije vidio.

These are still understandable, but the focus changes slightly.

One important thing: short words like je are clitics, so they usually cannot stand alone at the beginning of the clause in neutral style.

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

So nouns such as:

• policajka
• auto
• vozač
• pješake

do not automatically show whether English should use a or the. That comes from context.

Depending on the situation, the sentence could correspond to:

• A policewoman stopped a car...
• The policewoman stopped the car...

In practice, the surrounding context tells you which English article makes sense.

This is about aspect, which is very important in Croatian.

• zaustaviti = perfective → to stop something as a completed action
• zaustavljati = imperfective → to be stopping, to stop repeatedly, or to describe the action as ongoing/habitual

Here the sentence describes one completed event, so zaustavila is the natural choice.

So:

• Policajka je zaustavila auto = The policewoman stopped the car
• Policajka je zaustavljala aute = The policewoman was stopping cars / used to stop cars

In this sentence, the completed-action meaning fits best.