Već sam joj ga pokazala, ali ga ona nije odmah primijetila.

Joj means to her. It is the short dative form of ona.

Ga is the short accusative form meaning him or it, depending on the context. In this sentence, it refers back to something already known from the conversation.

So pokazala joj ga means showed it/him to her.

Because the verb pokazati can take:

• an indirect object: joj = to her
• a direct object: ga = it/him

So the structure is:

• I showed
• it/him
• to her

Croatian often uses both short pronouns together like this.

Because Croatian past participles agree with the subject in gender and number.

• pokazala = the speaker is female
• pokazao = the speaker is male

So this sentence tells us that the speaker is a woman.

The same thing happens later with primijetila, which agrees with ona and shows that the person who did not notice it is also female.

Croatian past tense is formed with:

• a form of biti (sam, si, je, smo...)
• plus the past participle (pokazala)

So:

• sam pokazala = I showed

But sam is a clitic: a short unstressed word that usually goes near the beginning of the clause, not necessarily right next to the participle.

That is why Croatian says:

• Već sam joj ga pokazala

rather than a more English-like word order.

Short unstressed words in Croatian tend to follow a fairly fixed clitic order.

Here the order is:

• sam = auxiliary
• joj = dative pronoun
• ga = accusative pronoun

So sam joj ga is the normal standard order.

A learner does not need to memorize every possible clitic rule at once, but it is useful to notice that these little words usually cluster together in a set pattern.

Već means already.

It shows that the action happened before the point we might expect or before the next event in the sentence.

So the idea is:

• I had already shown it to her, but...

It helps create the contrast with the second clause: even though the speaker had already shown it, she still did not notice it immediately.

Because the second verb also needs its own object.

• pokazala joj ga = showed it to her
• ga ona nije odmah primijetila = she did not notice it right away

Even though it is the same it/him, Croatian still expresses it again because primijetiti also needs a direct object here.

That is true: Croatian often omits subject pronouns because the verb form already shows the person and number.

So a shorter version could be:

• ali ga nije odmah primijetila

Adding ona makes the subject more explicit and often slightly contrastive or emphatic:

• but she did not notice it right away

So ona is not strictly necessary, but it adds focus.

This is the negative past tense.

Croatian past tense normally uses an auxiliary plus a participle:

• je primijetila = she noticed

In the negative, the auxiliary becomes:

• nije = did not / has not

So:

• nije primijetila = she did not notice

You do not say ne je primijetila. The negative form is built into nije.

Odmah means immediately, right away, or at once.

Here it modifies primijetila:

• nije odmah primijetila = did not notice right away

Croatian adverbs can often move around more than in English, but this placement is very natural and clear.

Yes. Both verbs here are perfective, which fits the meaning of single completed events.

• pokazati = to show as a completed act
• primijetiti = to notice at a particular moment

That matches the sentence well:

• the speaker showed it once
• the other woman failed to notice it immediately

If imperfective verbs were used instead, the meaning would shift toward something more ongoing, repeated, or less bounded.

Yes.

Croatian pronouns follow grammatical gender, so ga can refer to:

• a male person = him
• a masculine noun that English would call it

So the exact English translation depends on what noun ga refers to in the wider context.