Learn Hardcore Croatian: Večeras ćemo prošetati kroz park poslije posla. - Tonight we will take a walk through the park after work.

Yes. With many verbs whose infinitive ends in -ti, Croatian allows you to drop the final -i in the infinitive and attach the future auxiliary to the end:

Večeras ćemo prošetati kroz park poslije posla.
Večeras prošetat ćemo kroz park poslije posla.

These two are both correct and mean the same thing.

A few notes:

In everyday speech, ćemo prošetati is more common and sounds more neutral.
prošetat ćemo is also correct and you will hear it often; it’s especially common when people want to keep the clitic (ćemo) in the “second position” in the sentence (after the first stressed element).

Why is the verb prošetati used instead of šetati? What is the difference?

Croatian distinguishes imperfective and perfective aspects:

šetati – imperfective: to walk, to be walking (ongoing/habitual)
prošetati – perfective: to go for a walk (a single, completed walk)

In your sentence:

Večeras ćemo prošetati kroz park…
→ Focuses on one whole walk that will start and finish this evening.

If you say:

Večeras ćemo šetati kroz park.
→ Emphasizes the activity (we will be walking / will spend time walking), not so much that it’s a single completed event.

Both are grammatically correct; the aspect slightly changes the nuance.

Could I say Večeras ćemo šetati kroz park poslije posla? Does that change the meaning much?

Yes, that is correct, and the difference is only in aspect and nuance:

prošetati (perfective) – one walk, seen as a complete event:
- Večeras ćemo prošetati kroz park… = We’ll go (take) a walk through the park tonight after work.
šetati (imperfective) – the action of walking, duration/activity:
- Večeras ćemo šetati kroz park… = We’ll be walking in/through the park tonight after work.

In practice, both often translate the same in English. Using prošetati just emphasizes “a nice, bounded walk,” like an outing, rather than just the motion of walking.

What does the preposition kroz mean here, and which case does park take?

kroz means through and it always takes the accusative case.

kroz park = through the park (accusative)

park is a masculine inanimate noun:

nominative singular: park
accusative singular (same form): park

So you don’t see a form change here, but grammatically it is in the accusative after kroz.

Compare:

Idemo u park. – We are going to the park. (u
- accusative = movement to)
Šetamo u parku. – We are walking in the park. (u
- locative = location)
Šetamo kroz park. – We are walking through the park. (kroz
- accusative = movement through)

Why is it poslije posla, and what case is posla in?

poslije means after and it normally takes the genitive case.

posao – nominative singular (job, work)
posla – genitive singular
poslije posla – after work (literally “after of-work”)

So:

poslije + genitive = after something

Other common prepositions that also require the genitive:

prije posla – before work
nakon posla – after work
umjesto posla – instead of work

Can I say nakon posla instead of poslije posla?

Yes, you can. Both are correct:

poslije posla – after work
nakon posla – after work

Differences in usage:

poslije is slightly more conversational and very common.
nakon can sound a bit more formal or written, especially in official texts, though in everyday speech it’s also fine.

In your sentence, both sound natural:

Večeras ćemo prošetati kroz park poslije posla.
Večeras ćemo prošetati kroz park nakon posla.

Why doesn’t park change form here? Shouldn’t cases change the ending?

It actually is changing case (it is accusative), but for this type of noun, the form looks the same in nominative and accusative singular.

Masculine inanimate nouns (like park) often have:

Nominative sg.: park
Accusative sg.: park (same shape)

Examples:

Ovo je park. (nominative: This is a park.)
Idemo kroz park. (accusative: We are going through the park.)

So even though kroz requires the accusative, the word park does not change its ending in this particular form.

Why is there no mi (we) in the sentence? Could I say Mi ćemo prošetati…?

Croatian usually drops subject pronouns when the verb ending makes the subject clear.

ćemo (ending -mo) already shows it is we.
So Večeras ćemo prošetati… naturally means Tonight we will take a walk…

You can add mi for emphasis or contrast:

Mi ćemo večeras prošetati kroz park, a oni će ostati doma.
We will take a walk tonight, but they will stay at home.

So:

Without mi – neutral, most common.
With mi – adds emphasis or contrast, or can be used if you want to be very explicit.

Can večeras appear in a different place in the sentence?

Yes. Croatian word order is relatively flexible, especially for adverbs of time like večeras (tonight).

All of these are possible and natural, with small nuances of emphasis:

Večeras ćemo prošetati kroz park poslije posla.
Poslije posla večeras ćemo prošetati kroz park.
Večeras poslije posla ćemo prošetati kroz park.

The most neutral and common in everyday speech is the original:

Večeras ćemo prošetati kroz park poslije posla.

Putting večeras first tells the listener right away when this will happen.

Where must the word ćemo stand? Can I move it freely?

Ćemo is a clitic (an unstressed short word) and in Croatian clitics have strict placement rules: they usually go into the second position in the clause.

Basic pattern:

First stressed word or phrase
Then the clitics (like ću, ćeš, će, ćemo, ćete, će)
Then the rest of the sentence

Examples:

Večeras ćemo prošetati kroz park.
– first word: Večeras → then ćemo

If you bring the verb in front:

Prošetat ćemo kroz park.
– first word: Prošetat → then ćemo

You generally cannot put ćemo at the very end or far later in the sentence like in English “We will tonight walk through the park”. The future auxiliary must stay in or very near that “second position” slot.

Could I say Večeras idemo prošetati kroz park poslije posla instead? What is the difference?

Yes, that is also correct:

Večeras idemo prošetati kroz park poslije posla.
Literally: Tonight we are going to go for a walk through the park after work.

Compared to:

Večeras ćemo prošetati kroz park poslije posla.

Nuance:

ćemo prošetati – a straightforward future statement.
idemo prošetati – can sound a bit more planned / decided or like you’re announcing an arrangement, similar to English “We are going to go for a walk” or “We’re going for a walk”.

In everyday conversation, idemo + infinitive is very common when talking about near‑future plans or suggestions:

Idemo jesti. – Let’s go eat.
Idemo gledati film. – Let’s go watch a movie.

Is there any difference between poslije and posle?

Yes, this is a dialectal / standard‑language difference across the region:

In standard Croatian, the usual form is poslije.
posle is typical for Serbian and some regional varieties, but it is not standard in Croatian.

So in standard Croatian sentences, you should use:

poslije posla, not posle posla.