اتاق من از اتاق برادرم روشن تر است.

The sentence follows a very common Persian pattern for comparisons:

A از B adjective-تر است

So here:

• اتاق من = my room
• از اتاق برادرم = than my brother’s room
• روشن‌تر = brighter
• است = is

Literally, it is something like:

My room, from my brother’s room, brighter is.

Natural English: My room is brighter than my brother’s room.

Yes, از often means from, but in comparisons it also means than.

So in this sentence:

• از اتاق برادرم = than my brother’s room

This is very normal in Persian. After a comparative adjective like روشن‌تر (brighter), Persian usually uses از before the thing being compared.

Examples:

• این کتاب از آن کتاب بهتر است.
  This book is better than that book.

• علی از رضا بلندتر است.
  Ali is taller than Reza.

So a learner should remember:

• از = from
• از after a comparative = than

-تر is the comparative ending, similar to English -er or more.

So:

• روشن = bright / light
• روشن‌تر = brighter

This suffix can be added to many adjectives:

• بزرگ = big

• بزرگ‌تر = bigger

• سریع = fast

• سریع‌تر = faster

• خوب = good
• بهتر = better

So in your sentence, روشن‌تر simply means brighter.

Both styles are seen, but روشن‌تر is usually the more careful modern spelling.

What is happening is:

• روشن
  • تر

Because Persian script has spacing conventions that are a bit different from English, this comparative suffix may appear:

• separated: روشن تر
• with a half-space / joiner: روشن‌تر

They mean the same thing.

For learners, the important point is grammatical, not typographic:

• روشن‌تر = brighter

برادرم is made of:

• برادر = brother
• -م = my

So:

• برادرم = my brother

This ending -م is a very common possessive ending in Persian.

Other examples:

• کتابم = my book
• دوستم = my friend
• خانه‌ام = my house

So اتاق برادرم means:

• اتاق = room
• برادرم = my brother

Together: my brother’s room

Literally: room of my brother

Persian allows both styles:

1. noun + separate pronoun

   • اتاق من = my room

2. noun + possessive ending

   • اتاقم = my room

So your sentence could also be said as:

اتاقم از اتاق برادرم روشن‌تر است.

Both are correct.

Very often:

• اتاق من can sound a bit more explicit or slightly more emphasized
• اتاقم can sound more natural and compact in everyday speech

Similarly:

• برادر من = my brother
• برادرم = my brother

The suffix form is extremely common.

Yes — this is because of the ezafe construction.

Persian often links nouns and modifiers with a short -e / -ye sound called ezafe:

• اتاقِ من = my room
• اتاقِ برادرم = my brother’s room

But in normal Persian writing, this short vowel is usually not written.

So although you see:

• اتاق من
• اتاق برادرم

you usually pronounce them as:

• otāq-e man
• otāq-e barādaram

This is one of the most important things for English-speaking learners to get used to: Persian often leaves short vowels unwritten.

Yes, sometimes Persian can omit repeated words if the meaning is clear, but in this sentence keeping اتاق makes the comparison very clear and natural:

اتاق من از اتاق برادرم روشن‌تر است.

If the context is obvious, speakers may use shorter phrasing in conversation. But for learners, the full version is very helpful because it clearly shows the structure:

• my room
• than my brother’s room
• brighter is

So the repeated اتاق is not strange — it is a normal and clear way to say it.

In Persian, predicate adjectives usually come before the verb است.

So:

• اتاق من روشن است.
  My room is bright.

And in the comparative:

• اتاق من از اتاق برادرم روشن‌تر است.
  My room is brighter than my brother’s room.

This is very normal Persian word order:

subject + comparison phrase + adjective + copula

English says:

• My room is brighter

Persian says:

• My room brighter is

است is the third-person singular form of to be: is.

So in this sentence it functions just like English is:

• روشن‌تر است = is brighter

In spoken Persian, است is often shortened or dropped, especially in informal speech.

For example, a speaker may say something closer to:

اتاق من از اتاق برادرم روشن‌تره.

Here -ه is the informal spoken equivalent of است.

So:

• formal/written: است
• informal/spoken: often -ه

A natural pronunciation is roughly:

otâgh-e man az otâgh-e barâdar-am roshan-tar ast

A slightly more learner-friendly breakdown:

• اتاق من → otâgh-e man
• از → az
• اتاق برادرم → otâgh-e barâdar-am
• روشن‌تر → roshan-tar
• است → ast

A few useful notes:

• The written ق in اتاق is pronounced here as a deep gh sound.
• The ezafe sound is heard even though it is usually not written:
  • otâgh-e man
  • otâgh-e barâdar-am

In this sentence, yes, روشن is a very natural word.

روشن can mean:

• bright
• light
• well-lit
• clear

For rooms, it often means the room has more light.

So:

• اتاق روشن = a bright room / a light room

In this sentence, روشن‌تر most naturally means brighter or more well-lit.

Depending on context, English might translate it as:

• brighter
• lighter
• better lit

But brighter is the most straightforward translation.

Yes, absolutely.

That version means the same thing:

اتاقم از اتاق برادرم روشن‌تر است.
My room is brighter than my brother’s room.

Here:

• اتاقم = my room

This is often a very natural choice in Persian. Both versions are correct:

• اتاق من ...
• اتاقم ...

A learner should understand and eventually become comfortable with both.

It is basically neutral standard Persian.

Why?

• The structure is standard.
• The vocabulary is normal.
• The final است gives it a more complete written/standard feel.

In casual speech, someone might say:

اتاقم از اتاق برادرم روشن‌تره.

That sounds more conversational.

So you can think of the original sentence as:

• correct
• natural
• slightly more written or careful than everyday casual speech

This sentence is a great example of several important Persian patterns:

1. Possession

   • اتاق من = my room
   • برادرم = my brother

2. Ezafe

   • pronounced but usually not written
   • اتاقِ من
   • اتاقِ برادرم

3. Comparison

   • از = than
   • -تر = comparative suffix

4. Predicate adjective

   • adjective comes before است

5. Copula

   • است = is

So even though the sentence is short, it teaches a lot of core Persian grammar.