U motivacijskom pismu istaknite radno iskustvo.

Because u often means in or inside, and when it refers to a location, it normally takes the locative case in Croatian.

So:

• basic form: motivacijsko pismo
• after u for location: u motivacijskom pismu

This is similar to saying in the letter rather than just the letter.

A useful contrast:

• u školi = in the school → location, so locative
• u školu = into the school → motion/direction, so accusative

In this sentence, there is no movement, just location, so locative is used.

Because the adjective has to agree with the noun in gender, number, and case.

The noun is:

• pismo = neuter singular

In the dictionary/basic form, the adjective is:

• motivacijski = motivational
• neuter singular nominative: motivacijsko

But after u with location, the phrase goes into the locative singular, so the adjective changes too:

• motivacijsko pismo → nominative
• u motivacijskom pismu → locative

So motivacijskom is simply the locative singular form that matches pismu.

For the same reason: the noun is in the locative singular after u when u means in.

• basic form: pismo
• locative singular: pismu

So:

• pismo = letter
• u pismu = in the letter

This is a very common pattern with neuter nouns in Croatian.

Istaknite is the imperative form, meaning it is a command or instruction.

More specifically, it is the:

• 2nd person plural imperative
• also used as the polite singular imperative

So it can mean:

• speaking to several people: Highlight ...
• speaking politely to one person: Please highlight ...

This is very common in instructions, job-application advice, manuals, and formal writing.

Related forms:

• istakni = informal singular command
• istaknite = plural or polite singular command

Because it is the direct object of the verb istaknite, so it is in the accusative case.

The noun phrase is:

• radno iskustvo = work experience

For this neuter singular noun, the accusative looks the same as the nominative:

• nominative: radno iskustvo
• accusative: radno iskustvo

So even though it is the object, its form does not change visibly.

The adjective radno also agrees with iskustvo in gender, number, and case.

Croatian often leaves out possessive words like your when they are obvious from context.

In English, you might naturally say:

• Highlight your work experience

In Croatian, that idea is often understood without adding your:

• Istaknite radno iskustvo.

If you wanted to make it explicit, you could say:

• Istaknite svoje radno iskustvo.

But in many contexts, especially instructions or advice, svoje is unnecessary because it is already clear whose work experience is meant.

Croatian often expresses this kind of idea with an adjective + noun combination rather than a noun modifying another noun.

So English:

• work experience

becomes Croatian:

• radno iskustvo

Here:

• radno = work-related
• iskustvo = experience

This pattern is extremely common in Croatian. English frequently uses noun stacks, but Croatian usually prefers an adjective or a prepositional phrase.

Yes. Croatian word order is more flexible than English word order.

The given sentence:

• U motivacijskom pismu istaknite radno iskustvo.

puts u motivacijskom pismu first, which sets the context right away: in the motivation letter.

You could also say:

• Istaknite radno iskustvo u motivacijskom pismu.

That is also correct. The difference is mainly one of focus and style, not basic meaning.

The original version sounds natural because it starts with the setting or frame, which is common in instructions.

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

• istaknuti = perfective
• isticati = imperfective

The form istaknite comes from istaknuti and suggests a complete, single action: make sure you highlight it.

That fits this sentence well, because the advice is about doing one clear thing in the letter.

If you used an imperfective form, it would sound more like an ongoing or repeated action, which is less natural here.

So in short:

• istaknite = highlight it / make it stand out
• good for one instruction with a clear result

Yes, it is a common set phrase in Croatian.

• motivacijsko pismo is the usual term for a motivation letter
• in job-application contexts, it often overlaps with what English speakers may call a cover letter

Because it is a standard expression, learners should treat it as a useful chunk:

• u motivacijskom pismu
• pisati motivacijsko pismo
• poslati motivacijsko pismo

Learning whole phrases like this is often easier than translating word by word.