Poslije škole vraćam se kući s bratom.

Because poslije requires the genitive case.

The base form is škola (school), but after poslije it changes to škole:

• škola = school
• poslije škole = after school

This is very common in Croatian: certain prepositions automatically force a specific case, and poslije takes the genitive.

Vraćam se means I am returning / I return / I go back.

The little word se is important because it makes the verb reflexive. Without it, vraćam usually means I return something / I give something back:

• Vraćam knjigu. = I am returning the book.
• Vraćam se kući. = I am returning home.

So se is not optional here. It is part of the verb meaning.

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

• vraćam se = imperfective
• vratim se = perfective

In this sentence, vraćam se is the natural choice because it describes a normal, ongoing, or habitual action: returning home after school.

Vratim se usually refers to a completed return and is often used in future-type contexts, for example:

• Kad se vratim kući, nazvat ću te. = When I get back home, I’ll call you.

So for a simple statement like this one, vraćam se is the expected form.

Yes, it is present tense.

But in Croatian, just like in English, the present tense can describe:

• something happening now
• a habitual action
• a general routine

So this sentence can mean something like:

• I’m returning home with my brother after school
• or After school, I go home with my brother

The exact interpretation depends on context.

Because Croatian uses kući in the fixed expression meaning home after verbs of motion.

So:

• kuća = house
• kući = home / to home

With verbs like ići, doći, vratiti se, vraćati se, Croatian normally says:

• Idem kući. = I’m going home.
• Vraćam se kući. = I’m returning home.

This is more idiomatic than using the basic noun form kuća.

Because kući and u kuću are close, but not exactly the same.

• kući usually means home in the general, natural sense
• u kuću means into the house, which sounds more literal and physical

So:

• Vraćam se kući. = I’m returning home.
• Ulazim u kuću. = I’m entering the house.

If you want the normal idea of going/returning home, kući is the usual choice.

Because the preposition s here means with, and after s Croatian uses the instrumental case.

The base form is brat (brother), and the instrumental singular is bratom:

• brat = brother
• s bratom = with (my/the) brother

So bratom is instrumental singular.

Usually, s bratom is the normal form.

Croatian has both s and sa, but sa is mostly used when pronunciation is easier that way, especially before certain consonants or clusters, for example:

• sa sestrom
• sa mnom

Before bratom, simple s is standard and natural:

• s bratom

So sa bratom would sound unusual to most speakers.

Croatian often leaves out possessives like moj when the meaning is clear from context, especially with family members.

So s bratom can naturally mean:

• with my brother
• or sometimes with the brother / with a brother, depending on context

If you want to be explicit, you can say:

• s mojim bratom = with my brother

Also, Croatian has no articles like a or the, so context does a lot of work.

Yes. Croatian word order is much more flexible than English word order because case endings show the grammatical relationships.

This sentence can be rearranged in different ways, for example:

• Poslije škole vraćam se kući s bratom.
• Vraćam se kući s bratom poslije škole.
• Poslije škole se vraćam kući s bratom.

These versions are all understandable, but the emphasis and rhythm change slightly. The original sentence puts after school first, so the time expression is highlighted.

No. You can also use nakon.

Both are possible:

• Poslije škole vraćam se kući s bratom.
• Nakon škole vraćam se kući s bratom.

They both mean after school. In many situations they are interchangeable. Poslije often sounds a bit more everyday and conversational, while nakon can sound a little more neutral or formal, but both are perfectly normal.

Normally, it means after school in the same general sense as English: after the school day or after classes.

It does not usually make you think specifically about the building itself. It is a time expression, not mainly a location expression.

So learners can usually understand poslije škole as the natural Croatian equivalent of after school.