Sutra ću svratiti do trgovine po kruh.

Because Croatian forms the future tense with a short auxiliary from htjeti plus the infinitive.

Here:

• ću = I will
• svratiti = infinitive to stop by / drop in

In Croatian, these short auxiliary forms are clitics, which means they usually go in the second position in the sentence or clause.

So:

• Sutra ću svratiti... = literally Tomorrow I will stop by...

You can also put the verb first:

• Svratit ću do trgovine po kruh.

In that version, the infinitive usually loses its final -i before ću:

• svratiti + ću → svratit ću

Both are correct.

Svratiti means something like:

• to drop by
• to stop by
• to pop in
• to make a quick stop

It suggests a short visit or stop, not a long stay.

So this sentence is not just I will go to the shop. It has the nuance of:

• I’ll stop by the shop
• I’ll swing by the shop

That fits well with everyday errands.

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

• svratiti = perfective
• svraćati = imperfective

In this sentence, the speaker is talking about one completed action in the future: a single stop tomorrow. That is why svratiti is natural.

Very roughly:

• svratiti = stop by once / make a stop
• svraćati = be stopping by regularly / habitually / repeatedly

So:

• Sutra ću svratiti... = one specific stop tomorrow

Trgovine is in the genitive singular.

That is because the preposition do normally takes the genitive.

So:

• trgovina = nominative
• do trgovine = to the shop / up to the shop

This is a very common pattern:

• do kuće = to home / as far as home
• do škole = to the school
• do grada = to the town

Good question. Both can relate to going to a shop, but they are not exactly the same.

• do trgovine = to the shop / by the shop / up to the shop
• u trgovinu = into the shop

With svratiti, do + genitive is very natural and idiomatic:

• svratiti do trgovine = stop by the shop

It focuses on the stop as a destination.

You may also hear:

• svratiti u trgovinu

That also works, especially if you want to emphasize actually going inside the store. But svratiti do trgovine is a very common everyday way to say stop by the shop.

Here po kruh means:

• for bread
• to get bread
• to pick up bread

In Croatian, ići / svratiti / poslati nekoga po nešto is a very common pattern for going to fetch or buy something.

So:

• otići po kruh = go get bread
• svratiti po kruh = stop by for bread
• poslati nekoga po kruh = send someone for bread

It does not mean because of bread or about bread. It means the purpose of the trip.

Here kruh is in the accusative singular.

The important thing is that with po in the sense of to fetch / get, Croatian uses the accusative.

The reason it may not look different is that kruh is a masculine inanimate noun, and for many such nouns, the accusative singular looks the same as the nominative singular.

So:

• nominative: kruh
• accusative: kruh

A clearer example with a feminine noun:

• po vodu = for water
• po knjigu = for a book

Those forms visibly show the accusative better.

Because after po in this meaning (to fetch / to get), standard Croatian uses the accusative, not the genitive.

So:

• po kruh = correct in this sentence

You may see kruha in other contexts, because kruha is a genitive form:

• nema kruha = there is no bread
• komad kruha = a piece of bread

In some colloquial or regional usage, genitive forms can appear in quantity-like meanings, but for this construction, the standard form is:

• po kruh

Because Croatian has no articles like English a/an/the.

So Croatian often just says:

• trgovina = shop / a shop / the shop
• kruh = bread / the bread

Whether English needs a or the depends on the context, but Croatian usually leaves that unstated.

That is why:

• do trgovine can mean to the shop
• po kruh can mean for bread

Yes. Croatian word order is fairly flexible, although some orders are more natural than others.

This sentence:

• Sutra ću svratiti do trgovine po kruh.

could also appear as:

• Svratit ću sutra do trgovine po kruh.
• Do trgovine ću sutra svratiti po kruh.

The meaning stays basically the same, but the focus changes.

For example:

• Sutra ću... puts tomorrow first for emphasis
• Do trgovine ću... emphasizes the destination
• Po kruh ću... would emphasize the purpose

Still, the original sentence is very natural and neutral.

Yes, dućan is also very common.

• trgovina = store / shop
• dućan = shop, often a bit more everyday/colloquial

So you could also hear:

• Sutra ću svratiti do dućana po kruh.

Both are natural.
Trgovina is a bit more neutral/general; dućan often sounds a bit more conversational.

It is a bit more specific.

The sentence says that tomorrow the speaker will:

1. stop by the shop
2. for the purpose of getting bread

So it is not just the abstract fact of buying bread. It includes the small errand-like action of stopping by somewhere.

A simpler sentence like:

• Sutra ću kupiti kruh.

means:

• Tomorrow I’ll buy bread.

That focuses more directly on the purchase itself.

By contrast:

• Sutra ću svratiti do trgovine po kruh.

sounds more like:

• Tomorrow I’ll stop by the shop for some bread.

Sutra means tomorrow and functions as a time adverb.

It does not have to be at the beginning, but beginning position is very common because it sets the time frame right away.

You could also say:

• Ću sutra svratiti... → not natural, because ću should not start the clause like that in normal usage
• Svratit ću sutra do trgovine po kruh. → natural
• Do trgovine ću svratiti sutra po kruh. → possible, but less neutral

So sutra at the start is a very normal, natural choice.

It is neutral everyday Croatian.

Nothing in it is especially formal or especially slangy. You could say it in normal conversation without any problem.

• sutra = standard
• ću = standard future auxiliary
• svratiti = common everyday verb
• trgovina = standard, neutral
• kruh = standard word for bread in Croatian

So this is a very useful model sentence for real-life speech.