Learn Hardcore Croatian: Kad odlučimo gdje ćemo ljetovati, odmah ću uzeti putovnicu i spremiti je na policu. - When we decide where we will spend the summer, I will immediately take the passport and put it on the shelf.

In Croatian, time clauses introduced by kad (when) usually use the present tense even when they refer to the future. The main clause then carries the future tense.

Kad odlučimo gdje ćemo ljetovati, – literally: When we decide where we will spend the summer,
odmah ću uzeti… – I will immediately take…

Using kad ćemo odlučiti is generally felt as clumsy or non‑standard in this kind of sentence. The natural pattern is:

Kad + present, main clause in future
- Kad završim posao, otići ću kući. – When I finish work, I’ll go home.
- Kad budeš imao vremena, nazovi me. – (Here *budeš imao is a special future-like form, but still not ćeš imati.)*

So kad odlučimo is correct and idiomatic; kad ćemo odlučiti should be avoided here.

What is the difference between kad and kada?

Kad and kada mean the same thing: when.

Kad odlučimo gdje ćemo ljetovati…
Kada odlučimo gdje ćemo ljetovati…

Both are correct. Kad is shorter and more common in everyday speech; kada can sound a bit more formal or careful, but the difference is stylistic only. You can freely replace one with the other in this sentence.

Why is there a comma after ljetovati?

Because we have a subordinate clause followed by the main clause:

Subordinate (time) clause: Kad odlučimo gdje ćemo ljetovati
Main clause: odmah ću uzeti putovnicu i spremiti je na policu.

In Croatian, when a subordinate clause comes before the main clause, you normally separate them with a comma:

Kad dođeš kući, nazovi me.
Ako bude kiše, ostat ćemo doma.

If the order is reversed, you often don’t use a comma:

Nazovi me kad dođeš kući.
Ostat ćemo doma ako bude kiše.

Why is it gdje ćemo ljetovati and not gdje ljetovat ćemo? Where does ćemo go?

The word ćemo is a clitic (an unstressed auxiliary) and Croatian clitics usually go in the second position in the clause.

In the clause:

gdje ćemo ljetovati – where we will spend the summer

The first word is gdje (where), so ćemo must come second:

gdje (1st) + ćemo (2nd) + ljetovati

Forms like gdje ljetovat ćemo sound incorrect or at best very unnatural. The same rule applies elsewhere:

Što ćemo raditi sutra? – What will we do tomorrow?
Tada ćemo otići kući. – Then we will go home.

What exactly does ljetovati mean? Is it just to spend the summer?

Ljetovati roughly means to spend the summer (somewhere), especially in the sense of to go on summer vacation / holiday.

Typical use:

Ljetovat ćemo na Jadranu. – We’ll spend (our) summer on the Adriatic.
Gdje obično ljetuješ? – Where do you usually go for summer holidays?

It’s an intransitive verb here (no direct object). You just say ljetovati somewhere:

ljetovati u Hrvatskoj / u Italiji / na moru

Why is it putovnicu and not putovnica?

Putovnica (passport) is a feminine noun. In the sentence it is the direct object of the verb uzeti (to take), so it must be in the accusative singular:

Nominative (dictionary form): putovnica
Accusative singular (object): putovnicu

Compare:

Vidim putovnicu. – I see the passport.
Kupujem knjigu. – I’m buying a book. (nominative knjiga, accusative knjigu)

So uzeti putovnicu is grammatically the same pattern as uzeti knjigu.

What does je refer to in spremiti je na policu, and why is it in that position?

Je is the unstressed 3rd‑person singular feminine pronoun in the accusative, meaning her/it.

Here it refers back to putovnicu (passport), which is feminine:

…uzeti putovnicu i spremiti je na policu.
– …to take the passport and put it on the shelf.

Since je is a clitic, it has restricted positions. With an infinitive like spremiti, it normally comes right after the infinitive:

spremiti je – to put it away / to store it

Other examples:

Moram je vidjeti. – I have to see her/it.
Želim je kupiti. – I want to buy it.

Using je before spremiti (je spremiti) is technically possible in some constructions but is much less natural in modern standard usage.

Why is it na policu and not na polici?

Because na policu (accusative) expresses movement onto the shelf, while na polici (locative) expresses location on the shelf.

spremiti je na policu – to put it onto the shelf (there is movement to a new place)
putovnica je na polici – the passport is on the shelf (static location)

General rule with prepositions like na, u:

Accusative → movement (to / onto / into)
- staviti knjigu na stol – put the book on(to) the table
- ići u školu – go to school
Locative → location (on / in / at)
- knjiga je na stolu – the book is on the table
- u školi sam – I am at school

Why are uzeti and spremiti used here, and not uzimati and spremati?

Uzeti and spremiti are perfective verbs; uzimati and spremati are their imperfective counterparts.

Perfective verbs present an action as a single, complete event:

odmah ću uzeti putovnicu – I will (once) take the passport
(i) spremiti je na policu – and (once) put it on the shelf

That fits well with odmah (immediately) and with a one‑time future action.

Imperfective forms (uzimati, spremati) suggest ongoing or repeated actions:

Obično uzimam putovnicu i spremam je u ladicu.
– I usually take the passport and put it in the drawer. (habit)

So in this sentence, perfective uzeti, spremiti are the natural choice.

Why is the main clause in the future (odmah ću uzeti), but the kad‑clause uses present (kad odlučimo)?

This is a very typical Croatian pattern:

Time clause with kad → present tense (even for future time)
Main clause → future tense

So:

Kad odlučimo gdje ćemo ljetovati,
– present odlučimo used for a future moment: when we decide…
odmah ću uzeti putovnicu…
– future ću uzeti: I’ll immediately take the passport…

Other examples with the same pattern:

Kad dođeš, javit ću ti se. – When you come, I’ll contact you.
Kad padne mrak, upalit ćemo svjetla. – When it gets dark, we’ll turn on the lights.

So the mixture of present in the kad‑clause and future in the main clause is not a contradiction; it’s exactly how Croatian normally expresses future‑time conditions with kad.