Learn Hardcore Croatian: Pokušavam zapamtiti svaki datum u kalendaru. - I am trying to remember every date in the calendar.

Pokušavam comes from pokušavati (imperfective, present tense), and it matches the English “I am trying” – something in progress or happening regularly.

Pokušam (from pokušati) is perfective and is usually not used in the simple present in everyday speech; you more often see it in:

future: Pokušat ću zapamtiti… – I will try to remember…
past: Pokušao sam zapamtiti… – I tried to remember…

Why is zapamtiti in the infinitive form after pokušavam?

In Croatian, when you use a verb like pokušavati / pokušati (to try), it is normally followed by another verb in the infinitive, just like English “try to remember”:

pokušavam zapamtiti – I am trying to remember
pokušat ću zapamtiti – I will try to remember

So zapamtiti stays in the infinitive because it depends on pokušavam: try + (to) remember.

What is the difference between zapamtiti and pamtiti?

Both are related to memory, but aspect and nuance are different:

pamtiti – imperfective
- to remember (in general), to have something in your memory
- focuses on the state or ongoing remembering
- e.g. Još uvijek pamtim taj dan. – I still remember that day.
zapamtiti – perfective
- to memorize, to successfully commit something to memory at some point
- focuses on the moment of learning or achieving the memory
- e.g. Pokušavam zapamtiti svaki datum. – I am trying to memorize every date.

In your sentence, zapamtiti fits better because you are talking about the process/goal of learning and committing to memory, not just already having the dates remembered.

Could I say “pokušavam pamtiti svaki datum” instead? What would change?

You can say Pokušavam pamtiti svaki datum, but the meaning shifts slightly:

pokušavam zapamtiti svaki datum
– I’m trying to memorize each date (focus on successfully learning them, one by one).
pokušavam pamtiti svaki datum
– I’m trying to keep remembering each date (focus on the ongoing state of remembering, not on the act of learning them for the first time).

In most learning/memorizing contexts, zapamtiti is more natural.

What is the difference between svaki datum and sve datume? Could I say Pokušavam zapamtiti sve datume u kalendaru?

Yes, you can also say:

Pokušavam zapamtiti sve datume u kalendaru.

The difference:

svaki datum – every date, highlights each item individually
sve datume – all the dates, highlights the whole set as a group

Both are grammatically correct and close in meaning.
Subtle nuance:

svaki datum sounds a bit more like you’re going through dates one by one.
sve datume is a bit more collective: the entire list/calendar as a whole.

Which case is svaki datum in, and why?

Svaki datum is in the accusative singular:

svaki – nominative/accusative masculine singular form of “every”
datum → datum (same form in nominative and accusative for inanimate masculine nouns)

It’s accusative because it is the direct object of zapamtiti:

(Ja) pokušavam zapamtiti koga/što? – svaki datum.
(I) am trying to remember *what? – every date.*

Even though zapamtiti is in the infinitive, the object behaves as if the verb were fully finite:

Zapamtit ću svaki datum. – same case (accusative).

Why is it u kalendaru and not u kalendar?

In Croatian, u can take either:

accusative – when there is movement into something (into), or
locative – when it’s location inside something (in / inside).

Here we have a static location: the dates are in the calendar, not moving into it. So we use locative:

u kalendaru – in the calendar (locative singular)
u kalendar – into the calendar (accusative singular), would imply movement into the calendar (e.g. writing something into it).

So u kalendaru is correct in this context.

Why is there no ja (I) at the beginning of the sentence?

Croatian is a pro‑drop language: subject pronouns (ja, ti, on, ona, etc.) are often omitted because the verb ending already shows who the subject is.

pokušavam → the ending -am clearly shows 1st person singular (I).

You could say:

Ja pokušavam zapamtiti svaki datum u kalendaru.

but the ja is usually only added for emphasis or contrast:

Ja pokušavam zapamtiti, a ti ne. – I am trying to remember, and you aren’t.

How is pokušavati conjugated in the present tense?

Present tense of pokušavati (imperfective):

(ja) pokušavam – I try / I am trying
(ti) pokušavaš – you try / you are trying (singular, informal)
(on/ona/ono) pokušava – he/she/it tries
(mi) pokušavamo – we try
(vi) pokušavate – you try (plural or formal)
(oni/one/ona) pokušavaju – they try

In your sentence, pokušavam is 1st person singular.

Could I use sjetiti se instead of zapamtiti here?

You could form a similar sentence with sjetiti se, but the meaning changes:

zapamtiti – to memorize / to commit to memory
sjetiti se – to remember, to recall (something you have already learned)

Example:

Pokušavam zapamtiti svaki datum u kalendaru.
– I’m trying to memorize every date (learning them).
Pokušavam se sjetiti svakog datuma u kalendaru.
– I’m trying to remember/recall every date (they were already learned, but you’re trying to recall them now).

Also note:

sjetiti se is reflexive, so you must add se and use the genitive:
- svakog datuma (not svaki datum) with sjetiti se.

Can I change the word order, for example: Pokušavam svaki datum u kalendaru zapamtiti?

Yes, Croatian word order is relatively flexible, as long as you keep small clitics (like se, ga, ju) in the right place. Some variants:

Pokušavam zapamtiti svaki datum u kalendaru. – neutral, most natural.
Pokušavam svaki datum u kalendaru zapamtiti. – still correct; slightly emphasizes svaki datum u kalendaru.
Svaki datum u kalendaru pokušavam zapamtiti. – emphasizes every date in the calendar.
Zapamtiti svaki datum u kalendaru pokušavam. – possible, but sounds more poetic or marked.

For everyday speech, the original order is the most typical.