Learn Hardcore Croatian: I moj prijatelj je nervozan kad mora upoznati novu curu. - My friend is also nervous when he has to meet a new girlfriend.

It usually means and (joining words or clauses):
- Marko i Ana = Marko and Ana
- On radi i studira. = He works and studies.
At the beginning of a sentence, I often works like:
- and (continuing a story): I onda je otišao kući. = And then he went home.
- also / even: I moj prijatelj je nervozan… = My friend is also nervous / Even my friend is nervous…

So I moj prijatelj je nervozan… can be understood as:

And my friend is nervous… (continuing what was said before)
or
My friend is also nervous… / Even my friend is nervous… (adding him to a list).

It’s capitalized (I) only because it’s at the beginning of the sentence, not for any special grammatical reason.

Why is the verb je in the middle (I moj prijatelj je nervozan) and not right after the subject like in English?

Je is the 3rd person singular of biti (to be), and it’s a clitic – a short, “weak” word that normally wants to stand in the second position in the clause.

In neutral sentences, clitics (like je, se, ga, mu, etc.) usually come after the first stressed word or phrase.

Here, the first phrase is I moj prijatelj, so je naturally follows it:

I moj prijatelj je nervozan…

You could also say:

Moj prijatelj je nervozan… (without I) – still je comes after Moj prijatelj, which is the first phrase.

Putting je anywhere else (e.g. I je moj prijatelj nervozan) would sound wrong or at least very unnatural in standard Croatian.

Why is it nervozan and not nervozna or something else?

Nervozan is an adjective and it must agree in gender, number, and case with the noun it describes.

Subject: moj prijatelj – friend, masculine singular, nominative.
Adjective: nervozan – masculine singular nominative form.

Other forms would be:

nervozna – feminine singular (for moja prijateljica – my [female] friend)
nervozno – neuter singular (for dijete – child)
nervozni – masculine plural (for moji prijatelji – my friends)

So:

Moj prijatelj je nervozan. = My (male) friend is nervous.
Moja prijateljica je nervozna. = My (female) friend is nervous.

Why is present tense used: je nervozan kad mora upoznati? In English I might say “when he has to meet” – is this the same idea?

Yes, this is the same idea. Croatian uses the present tense for:

General truths / habits / repeated situations, just like English:
- On je nervozan kad mora govoriti pred ljudima.
  = He is nervous when he has to speak in front of people.

Your sentence describes a repeated, typical reaction:

Every time he has to meet a new girl, he becomes nervous.

So:

je nervozan kad mora upoznati novu curu
corresponds well to English is nervous when he has to meet a new girl (general, habitual).

What is the difference between kad and kada?

Kad and kada both mean when and are very close in meaning.

Kad – more informal, shorter, very common in speech and writing.
Kada – slightly more formal, can sound a bit more “careful” or literary, but is also common.

You can generally use them interchangeably:

Kad mora upoznati novu curu, nervozan je.
Kada mora upoznati novu curu, nervozan je.

Both: When he has to meet a new girl, he is nervous.

In fast speech, kada is almost always pronounced and written as kad.

What exactly does mora mean here, and how is morati + infinitive used?

Mora is the 3rd person singular present of morati = to have to / must.

Pattern:

morati + infinitive

Examples:

Mora raditi. = He/She has to work.
Moramo učiti. = We have to study.
Moram ići. = I have to go.

In your sentence:

mora upoznati = has to meet / must meet

So:

kad mora upoznati novu curu = when he has to meet a new girl

This is the standard way to express obligation, similar to English have to / must.

Why is it upoznati, not upoznavati or something like sresti?

Croatian verbs have aspect: perfective (completed action) vs imperfective (ongoing / repeated / process).

upoznati – perfective: to meet / get to know (for the first time), complete act
upoznavati – imperfective: to be meeting / getting to know (over time)

In your sentence:

kad mora upoznati novu curu
Focus is on the single act of first meeting her. Each time he’s supposed to meet a new girl, that specific event makes him nervous. So the perfective upoznati is natural.

Alternatives:

sresti (perfective to meet / run into) is more like bump into / encounter, often by chance:
- Kad mora sresti novu curu – would sound more like “when he has to come across a new girl,” which is not the usual way to say this.
upoznavati would stress a longer process:
- Kad mora upoznavati nove cure – more like “when he has to (continuously) be getting to know new girls,” i.e. over a period of time.

For a one-time first meeting each time, upoznati is the best choice.

Why is it novu curu and not nova cura?

This is about case. Croatian changes word endings depending on the grammatical role.

cura – base form (nominative, subject form)
curu – accusative singular (direct object form)

In the sentence, novu curu is what he has to meet, so it is the direct object of upoznati:

(On) mora upoznati koga? – novu curu.

Adjective nova also changes to match cura in gender, number, and case:

Nominative (subject): nova cura
- Nova cura je tu. = The new girl is here.
Accusative (object): novu curu
- Vidim novu curu. = I see the new girl.
- Mora upoznati novu curu. = He has to meet a new girl.

So novu curu is just the correct accusative form of nova cura.

What does cura mean exactly? Is it “girl”, “girlfriend”, or something else?

Cura is informal and can mean:

girl (young woman)
- Ona je dobra cura. = She is a good girl.
girlfriend
- Imam curu. = I have a girlfriend.
- Njegova cura = his girlfriend.

In your sentence novu curu is most naturally understood as a new girl (he’s going to date / meet romantically) – so loosely like “a new girl / a new girl he’s seeing”.

More neutral/formal word for girl / girlfriend (in the sense of “young woman”) is djevojka:

djevojka (nom.) → djevojku (acc.)
upoznati novu djevojku = to meet a new girl / young woman.

Cura is common in everyday speech; djevojka is a bit more neutral or formal.

Why is there no pronoun like on before mora? Shouldn’t it be kad on mora upoznati novu curu?

In Croatian, subject pronouns (ja, ti, on, ona, mi, vi, oni…) are often omitted, because the verb ending already shows the person.

mora clearly shows 3rd person singular (he/she/it).

So both are possible:

kad mora upoznati novu curu
kad on mora upoznati novu curu

The version with on adds emphasis, a bit like in English “when he has to meet a new girl (as opposed to someone else)”.

In a neutral sentence like yours, the natural choice is to leave on out.

Are there other natural ways to say this sentence in Croatian?

Yes, here are a few common variants with slightly different nuances:

I moj prijatelj se iznervira kad mora upoznati novu curu.
- My friend also gets nervous when he has to meet a new girl.
- se iznervira = “gets nervous” (becomes nervous), focusing on the change.
I moj prijatelj je nervozan kada treba upoznati novu curu.
- treba ≈ “needs to / is supposed to”, a bit softer than mora.
I moj prijatelj postane nervozan kad treba upoznati novu curu.
- postane nervozan = “becomes nervous”.
Without I:
- Moj prijatelj je nervozan kad mora upoznati novu curu.
  = My friend is nervous when he has to meet a new girl.

All of these are natural; the original sentence is already perfectly good, neutral Croatian.