i chaegeun ilgeulsurok jaemiisseoyo.

읽을수록 means the more (you) read it or as (you) read it more.

It is made from:

• 읽다 = to read
• -을수록 / -ㄹ수록 = the more..., increasingly as...

So:

• 읽다 → stem 읽-
• because the stem ends in a consonant, you add -을수록
• 읽을수록 = the more one reads

This pattern is very common in Korean:

• 보면 볼수록 = the more I see it
• 생각할수록 = the more I think about it
• 들으면 들을수록 = the more I listen

In this sentence, 읽을수록 재미있어요 means it gets more interesting the more you read it.

은 marks 이 책 (this book) as the topic of the sentence.

So 이 책은 means something like:

• as for this book
• this book, ...

That gives the sentence a natural topic-comment structure:

• 이 책은 = as for this book
• 읽을수록 재미있어요 = the more you read it, the more interesting it is

A very natural English translation is just This book gets more interesting the more you read it.

Korean often uses 은/는 when introducing what is being talked about, even when English would not explicitly say as for.

Good question. Even though 읽다 usually takes an object, Korean often leaves things implied when they are already understood from context.

Here, 이 책은 is the topic, and it is also understood to be the thing being read. So Korean does not need to repeat it as an object.

A more expanded version could be something like:

• 이 책은 읽으면 읽을수록 재미있어요
• literally: As for this book, if you read it and read it more, it is interesting

But Korean often prefers the shorter, smoother form:

• 이 책은 읽을수록 재미있어요

So the book is understood as the thing being read, even without 을.

Yes. Korean often omits subjects and objects when they are clear from context.

In English, we might say:

• This book gets more interesting the more you read it
• The more you read this book, the more interesting it gets

In Korean, the sentence does not explicitly say you or it, but both are understood:

• you = the person reading
• it = this book

This kind of omission is extremely normal in Korean.

-을수록 / -ㄹ수록 means the more..., the more... or increasingly as...

-면 means if/when...

Compare:

• 읽으면 재미있어요 = If/when you read it, it’s interesting
• 읽을수록 재미있어요 = The more you read it, the more interesting it becomes

So -을수록 shows a gradual increase or strengthening. It is not just a simple condition.

That is why 읽을수록 is the best choice here: the sentence is talking about how the book becomes more interesting over time.

Not really. Although English translations can sometimes sound similar, 읽을수록 specifically carries the idea of increasing degree.

A better literal sense is:

• to the extent that one reads
• the more one reads

So this sentence is not just saying reading the book is interesting. It is saying the interest grows with more reading.

재미있어요 comes from 재미있다, which literally means to have fun/interest and is used like to be interesting / enjoyable.

• 재미 = fun, interest
• 있다 = to exist, to have

So 재미있어요 means:

• it is interesting
• it is enjoyable
• it is fun

By contrast, 재미예요 would mean it is fun/interest, which is not the natural expression here.

In Korean, 재미있다 is the normal adjective-like verb for saying something is interesting or fun.

Yes. 재밌어요 is a very common contracted form of 재미있어요.

So these are basically the same in meaning:

• 재미있어요
• 재밌어요

The full form 재미있어요 may look slightly more standard or careful in writing, while 재밌어요 is extremely common in speech and informal writing.

The sentence suggests that the book may not reveal everything at once. As you keep reading, it becomes more engaging.

So the nuance is something like:

• This book gets more interesting the further you read
• The more you read this book, the more interesting it becomes

It often implies a gradual deepening of enjoyment, not just a one-time reaction.

Yes, Korean word order is flexible, so that sentence is grammatically possible.

But the emphasis changes slightly.

• 이 책은 읽을수록 재미있어요
  → starts with this book as the topic

• 읽을수록 이 책은 재미있어요
  → foregrounds the more you read first

The original version sounds very natural because it introduces the topic first and then comments on it.

You can change the ending depending on politeness level:

• 이 책은 읽을수록 재미있어요. = polite
• 이 책은 읽을수록 재미있어. = casual
• 이 책은 읽을수록 재미있습니다. = formal polite
• 이 책은 읽을수록 재밌어요. = polite, common contracted form

The grammar 읽을수록 stays the same. Only the final ending changes.

Yes. A very common related pattern is repeating the same verb:

• 읽으면 읽을수록 재미있어요
• literally: If you read it, and the more you read it, it’s interesting

This longer form can feel even more explicit about the the more..., the more... idea.

Other examples:

• 보면 볼수록 예뻐요 = The more I see it, the prettier it looks
• 알면 알수록 어려워요 = The more I learn, the harder it seems
• 생각하면 할수록 신기해요 = The more I think about it, the more amazing/strange it seems

So 읽을수록 is part of a very useful grammar pattern in Korean.