Zrak u sobi je topliji od zraka u parku.

The air in the room is warmer than the air in the park.

Breakdown of Zrak u sobi je topliji od zraka u parku.

• biti: to be
• u: in
• park: park
• od: than
• soba: room
• zrak: air
• topliji: warmer

Questions & Answers about Zrak u sobi je topliji od zraka u parku.

Why is it zrak at the beginning but zraka after od?

Zrak is in the nominative case because it is the subject of the sentence: The air (zrak) in the room is warmer….

After the preposition od (from/than) in this comparative structure, the noun must be in the genitive case, so zrak changes to zraka.

• zrak = nominative singular (subject)
• od zraka = genitive singular (because of od and the comparison)

So: Zrak u sobi je topliji od zraka u parku.
= The air in the room is warmer than the air in the park.

Why is it u sobi and u parku, and not u sobu or u park?

In Croatian, u + locative is used for location (where something is), and u + accusative is used for direction (where something is going).

Here we are describing where the air is, not where it’s going, so we use the locative:

• u sobi – in the room (locative of soba)
• u parku – in the park (locative of park)

If you talked about movement, you’d use the accusative:

• Idem u sobu. – I’m going into the room.
• Idem u park. – I’m going to the park.

How is the comparative topliji formed, and what is the base adjective?

The base adjective is topao (warm).

Comparative of topao is topliji (warmer). The formation involves:

1. Stem change: topao → topl-
2. Adding the comparative ending -iji for masculine singular:
   topl-
   • -iji = topliji

So:

• topao zrak – warm air
• topliji zrak – warmer air

Why is it topliji and not something like toplije here?

Topliji is the masculine singular form of the adjective and must agree with zrak, which is masculine singular.

• zrak – masculine singular → topliji
• voda (water) – feminine singular → toplija
• mlijeko (milk) – neuter singular → toplije

So in this sentence:

• Zrak (m.sg.) → topliji (m.sg. comparative adjective)

Can I say topliji nego zraka u parku instead of topliji od zraka u parku?

No, not in that form. Two points:

1. After nego, you do not keep the preposition od, so od and nego don’t combine.
2. With a simple noun phrase like this, Croatian prefers od + genitive.

Correct options are:

• Zrak u sobi je topliji od zraka u parku.
• Zrak u sobi je topliji nego zrak u parku. (less common, but grammatically possible)

In the first, od requires genitive: od zraka.
In the second, nego is followed by nominative: nego zrak u parku.

What is the difference between using od and nego in comparisons?

Both can mean than in comparisons, but they are used slightly differently:

1. od + genitive with adjectives in -iji is the most common pattern:

   • topliji od zraka – warmer than the air
   • veći od kuće – bigger than the house

2. nego is used:

   • After kao or nego što, or when you need a full clause:
     
     • Više volim čaj nego kavu. – I prefer tea to coffee.
     • Boljeg je okusa nego što sam očekivao. – It tastes better than I expected.
   • Often when there is a different case or grammatical form after the comparison.

In this specific simple noun comparison, od zraka is the most natural.

Why is there no word for “the” in zrak u sobi and zraka u parku?

Croatian has no articles (no the, no a/an). Definiteness is understood from context, word order, and sometimes from pronouns or other determiners.

So zrak u sobi can mean:

• the air in the room
• air in the room

English must choose the, but Croatian doesn’t need a separate word for it.

Do we really need to repeat zraka? Can we say something like “The air in the room is warmer than in the park” without repeating zrak?

Yes, you can avoid repeating zraka by changing the structure slightly:

• Zrak u sobi je topliji nego u parku.

Here, nego u parku is understood as than (the air) in the park, and the noun is simply omitted because it’s clear from context.

You could also say:

• Zrak u sobi je topliji od onog u parku.
  (than the one in the park) – using onog (genitive of onaj, “that one”) instead of repeating zraka.

Can I change the word order, for example: U sobi je zrak topliji od zraka u parku?

Yes, that word order is perfectly correct:

• U sobi je zrak topliji od zraka u parku.

Croatian word order is relatively flexible. Differences are usually about emphasis:

• Zrak u sobi je topliji… – neutral, “the air in the room is warmer…”
• U sobi je zrak topliji… – emphasizes the location “In the room, the air is warmer…”

Grammar and meaning are essentially the same.

Why do we need the verb je here? Could we drop it?

Grammatically, the verb je (3rd person singular of biti – to be) is required in a full, standard sentence:

• Zrak u sobi je topliji od zraka u parku.

In spoken, informal Croatian, people sometimes drop je, especially in short sentences:

• Zrak u sobi topliji od zraka u parku.

But for learning purposes and in correct written language, you should keep je.

Can zrak be used in the plural, like English “airs”?

Zrak normally behaves like a mass noun in this meaning (air as a substance), so the singular is standard.

Plural zraci does exist, but it usually means rays (as in rays of light):

• sunčevi zraci – sun rays

For air as in this sentence, you usually keep it singular and change the description around it:
zrak u sobi, zrak u parku, zrak na ulici, etc.

Does u sobi literally mean “in room” or “in the room”?

Literally, u sobi is “in room”: u (in) + sobi (locative of soba – room).

Because Croatian has no articles, u sobi can correspond to both:

• in the room
• in a room

In this particular sentence, natural English requires the room, but Croatian doesn’t mark that difference in the phrase itself. Context tells you whether it’s specific or general.