На балконе прохладнее, чем в комнате.

In Russian, the verb to be is usually omitted in the present tense.

So English It is cooler on the balcony than in the room becomes simply:

На балконе прохладнее, чем в комнате.

Russian does this very often:

• Я дома. = I am at home.
• Он занят. = He is busy.
• Здесь тепло. = It is warm here.

So this sentence is completely normal and complete without a verb.

Both балконе and комнате are in the prepositional case.

That is because they follow the prepositions:

• на in на балконе
• в in в комнате

Here, both prepositions answer the question where?, so they take the prepositional case:

• балкон → на балконе
• комната → в комнате

This is the usual pattern for location:

• в доме = in the house
• на улице = on the street
• в школе = at school / in the school

Russian uses different prepositions depending on how a place is conventionally viewed.

• в комнате = in the room
  A room is seen as an enclosed space, so Russian uses в.

• на балконе = on the balcony
  A balcony is usually treated as a kind of surface/open area, so Russian uses на.

This is something you often just have to learn with each noun, because Russian and English do not always match perfectly.

For example:

• в саду = in the garden
• на кухне = in the kitchen? No — actually на кухне in Russian, even though English says in the kitchen
• на вокзале = at the station

So на балконе is just the normal Russian choice.

Прохладнее is the comparative form of прохладный / прохладно.

It means cooler.

Russian often forms comparatives with -ее / -ей:

• быстрый → быстрее = faster
• тепло → теплее = warmer
• холодно → холоднее = colder
• прохладно → прохладнее = cooler

In this sentence, прохладнее functions like cooler in English:

• На балконе прохладнее = It’s cooler on the balcony

For a learner, the easiest way to think about it is: here it works like a predicative word describing the situation, not a noun.

Russian often uses words like:

• холодно = cold
• тепло = warm
• жарко = hot
• прохладно = cool

These describe the environment or conditions:

• В комнате тепло. = It’s warm in the room.
• На улице холодно. = It’s cold outside.

So прохладнее here means it is cooler, rather than a cooler balcony or something like that.

Чем is the normal word used to introduce the second part of a comparison after a comparative.

So:

• прохладнее, чем в комнате = cooler than in the room

This works like English than:

• лучше, чем... = better than...
• быстрее, чем... = faster than...
• интереснее, чем... = more interesting than...

So the structure is:

X + comparative + чем + Y

Here:

• На балконе = X
• прохладнее = comparative
• чем в комнате = than in the room

Yes, более прохладно is possible, but прохладнее is more natural and simpler here.

Compare:

• На балконе прохладнее, чем в комнате. — natural, everyday
• На балконе более прохладно, чем в комнате. — grammatical, but a bit heavier or more formal

Russian often prefers the short comparative form when it exists.

Russian usually does not need a dummy subject like English it.

English says:

• It is cool
• It is raining
• It is dark

Russian often just says:

• Прохладно.
• Идёт дождь.
• Темно.

So in this sentence, Russian does not need a word for it:

• На балконе прохладнее... literally something like On the balcony, cooler... but naturally meaning It’s cooler on the balcony...

Yes. Russian word order is flexible.

The sentence:

• На балконе прохладнее, чем в комнате.

could also be rearranged, for example:

• Прохладнее на балконе, чем в комнате.

But the original version is the most neutral and natural if you are talking first about the place.

Starting with На балконе puts the balcony in focus:

• As for the balcony, it’s cooler there than in the room.

Russian word order often changes emphasis rather than basic meaning.

Because чем introduces the comparison part of the sentence.

In standard Russian spelling, a comma is normally used before чем in this kind of comparison:

• Он выше, чем я.
• Сегодня теплее, чем вчера.
• На балконе прохладнее, чем в комнате.

So the comma here is standard punctuation.

You can use that as a rough grammar guide, but not as natural English.

A word-for-word breakdown is:

• На балконе = on the balcony
• прохладнее = cooler
• чем = than
• в комнате = in the room

But natural English needs it is:

• It’s cooler on the balcony than in the room.

So the Russian structure is more compact than the English one.

Not exactly. Прохладнее usually means cooler, not necessarily cold.

That is, the balcony is less warm than the room, but not necessarily unpleasantly cold.

A rough temperature scale in feeling might be:

• жарко = hot
• тепло = warm
• прохладно = cool
• холодно = cold

So прохладнее suggests a moderate decrease in warmth.

You could say:

На балконе прохладнее, чем в комнате?
= Is it cooler on the balcony than in the room?

Russian often forms yes/no questions just by intonation, without changing the word order.

You could also ask:

• Где прохладнее: на балконе или в комнате?
  = Where is it cooler: on the balcony or in the room?

This is a useful pattern to reuse:

• Здесь тише, чем там. = It’s quieter here than there.
• Утром лучше, чем вечером. = It’s better in the morning than in the evening.