U lipnju škole završavaju, pa su tramvaji ujutro malo prazniji.

Because after u meaning in with a time expression like a month, Croatian uses the locative case.

• dictionary form: lipanj = June
• locative form: lipnju
• so: u lipnju = in June

This is something you simply have to learn with month names, because their case forms are not always obvious from the base form.

In Croatian, months are normally not capitalized.

So you write:

• u lipnju
• u siječnju
• u prosincu

This is different from English, where June, January, December are capitalized.

Yes, škole is the nominative plural of škola.

So škole završavaju literally means schools are ending / finishing.

In this sentence, the plural is used generically: it means that schools in general finish in June. Croatian often uses this kind of plural when talking about something that happens broadly across the country or as a regular pattern.

You could also hear a singular version in some contexts, such as Škola završava u lipnju, but that would sound more like school ends in June as a general institution or in a specific situation.

Croatian often uses the present tense for:

• general truths
• regular yearly events
• scheduled or expected happenings

So škole završavaju does not have to mean only are ending right now. It can also mean something like:

• schools end
• schools finish
• schools are ending around that time

Here it expresses a regular yearly fact: when June comes, school ends, and that affects the tram traffic.

Not exactly.

Škole završavaju means that the school year / school term is ending, or that schools are finishing for the year.

It does not specifically mean students are graduating.

If you want to say students are graduating, Croatian would usually use different verbs, for example:

• učenici maturiraju = students are graduating from secondary school / taking final exams
• studenti diplomiraju = university students are graduating

So here the focus is on the school calendar, not on graduation.

Here pa means something like:

• so
• and so
• therefore
• which means that

It connects the two ideas:

• schools end in June
• therefore the trams are a bit emptier in the morning

So the logic is:

U lipnju škole završavaju, pa su tramvaji ujutro malo prazniji.
= In June schools end, so the trams are a little emptier in the morning.

Compared with something like zato or stoga, pa sounds very natural and everyday.

Because su is a clitic: a short, unstressed form of biti (to be). In Croatian, clitics usually go near the beginning of the clause.

That is why:

• pa su tramvaji... sounds natural

rather than:

• pa tramvaji su... which sounds wrong or unnatural in standard word order

A good beginner rule is:

• short forms like sam, si, je, smo, ste, su usually do not stand in a fully independent position
• they tend to appear early in the sentence or clause

So pa su tramvaji ujutro malo prazniji is the normal pattern.

Ujutro is an adverb meaning in the morning.

It is normally written as one word:

• ujutro = in the morning

So in this sentence:

• tramvaji su ujutro malo prazniji
• the trams are a little emptier in the morning

This is a fixed time expression, not just a random combination of u + jutro.

Other common time adverbs work similarly:

• popodne = in the afternoon
• navečer = in the evening

Prazniji is the comparative form of prazan = empty.

So:

• prazan = empty
• prazniji = emptier

In the sentence:

• malo prazniji = a little emptier

Croatian often forms comparatives with endings like -iji or -ji, depending on the adjective.

The base adjective here changes a bit:

• prazan → prazniji

You do not need a word meaning than unless you are explicitly comparing two things:

• Tramvaji su prazniji nego inače. = The trams are emptier than usual.

In your sentence, the comparison is understood from context.

Here malo means a little or slightly.

So:

• prazniji = emptier
• malo prazniji = a little emptier / slightly emptier

It softens the statement. The speaker is not saying the trams are dramatically empty, only that they are somewhat less full than usual.

This is very common in Croatian:

• malo bolji = a little better
• malo sporiji = a little slower
• malo hladnije = a little colder

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

So:

• škole can mean schools or the schools, depending on context
• tramvaji can mean trams or the trams

You figure out the exact meaning from the situation, context, and word order.

In this sentence, both nouns are being used generically:

• škole = schools in general
• tramvaji = the trams / trams in general, meaning the tram system people use in the morning

No. The word ujutro limits the meaning.

So the sentence means that in the morning, because schools are no longer in session, the trams are a bit emptier.

Without ujutro, the sentence would be broader:

• tramvaji su malo prazniji = the trams are a little emptier

With ujutro, it specifically points to the morning rush hour, when schoolchildren would normally be travelling.