munjangeul neomu gilge sseumyeon ihaehagi eoryeowoyo.

문장 means sentence, and -을 is the object particle.

So:

• 문장 = sentence
• 문장을 = sentence(s) as the thing being written

In this sentence, 문장을 is the object of 쓰면 (if you write), so it means if you write sentences...

A very literal breakdown is:

• 문장을 = sentences
• 너무 길게 = too long
• 쓰면 = if you write
• 이해하기 어려워요 = it is hard to understand

Korean often does not mark plural unless necessary, so 문장을 could mean a sentence or sentences depending on context.

길게 is the adverb form of 길다 (to be long).

Here is the difference:

• 길다 = to be long
• 긴 = long, used before a noun
  
  • example: 긴 문장 = a long sentence
• 길게 = longly / in a long way, used to describe an action
  
  • example: 길게 쓰다 = to write something long

So in 너무 길게 쓰면, 길게 modifies 쓰다:

• 길게 쓰다 = write at too great a length / write too long

If you said 긴 문장을 쓰면, that would also be natural and means if you write long sentences. The original sentence uses 길게 to focus on the manner of writing.

쓰면 is from 쓰다 (to write) plus -면, a conditional ending meaning if or sometimes when.

So:

• 쓰다 = to write
• 쓰면 = if you write

In this sentence, 문장을 너무 길게 쓰면 means:

• if you write sentences too long

The -면 form is very common for conditions:

• 가면 = if/when you go
• 먹으면 = if/when you eat
• 읽으면 = if/when you read

너무 can mean both too and very in real Korean, depending on context.

In this sentence, it clearly means too, because the whole point is that making sentences excessively long causes a problem:

• 문장을 너무 길게 쓰면 이해하기 어려워요.
• If you write sentences too long, they are hard to understand.

So here 너무 has the negative sense of excessively.

This is a very common Korean pattern:

• verb stem + -기 어려워요 = it is difficult to do

Here:

• 이해하다 = to understand
• verb stem = 이해하-
• 이해하기 = understanding / to understand
• 어려워요 = is difficult

So:

• 이해하기 어려워요 = it is difficult to understand

This pattern is used with many verbs:

• 읽기 어려워요 = it is hard to read
• 말하기 어려워요 = it is hard to speak
• 찾기 어려워요 = it is hard to find

It is more natural in English to translate this sentence as they are hard to understand rather than understanding is difficult, but both reflect the same Korean structure.

Because Korean needs to turn 이해하다 (to understand) into a noun-like form before saying it is difficult.

That is what -기 does.

• 이해하다 = to understand
• 이해하기 = understanding / to understand
• 이해하기 어려워요 = understanding is difficult / it is hard to understand

You cannot normally put two finite verb forms together like 이해해요 어려워요. The -기 form links the action to 어렵다 naturally.

Yes. Korean often leaves out subjects, topics, and objects when they are obvious from context.

In this sentence, English would often supply something like:

• they are hard to understand
• it is hard to understand them
• people will have difficulty understanding them

But Korean does not need to say all of that explicitly.

So 이해하기 어려워요 can be understood as:

• (they) are hard to understand
• it becomes hard to understand (them)

The thing being understood is already clear from the earlier part: the overly long sentences.

Yes, depending on context.

Because Korean often does not mark singular vs. plural clearly:

• 문장을 can mean a sentence
• or sentences

In English, If you write sentences too long... sounds the most natural as a general statement, so that is usually the best translation. But grammatically, Korean itself does not force one choice here.

어려워요 is the polite present form of 어렵다 (to be difficult).

So the ending -어요 / -아요 makes the sentence polite but not overly formal.

• 어렵다 = dictionary form
• 어려워요 = polite everyday form
• 어렵습니다 = more formal

This makes the whole sentence sound like normal polite spoken or written Korean.

Yes, 이해하기가 어려워요 is also correct.

The -가 marks 이해하기 as the subject of 어려워요:

• 이해하기 어려워요
• 이해하기가 어려워요

Both mean it is hard to understand.

The version without -가 is very common and sounds natural. Adding -가 can make the structure feel slightly more explicit or emphasize the understanding part.

Both are natural, but the focus is slightly different.

• 문장을 너무 길게 쓰면

  • literally: if you write a sentence too long
  • focuses on the act of writing in an overly long way

• 너무 긴 문장을 쓰면

  • literally: if you write a sentence that is too long
  • focuses more directly on the sentence as a long noun phrase

In everyday use, the meanings are very close. The original sentence sounds very natural and conversational.

Usually it refers to the reader's understanding, or understanding in general.

So the natural sense is:

• If you write sentences too long, they become hard to understand.

Korean does not specify for whom it is difficult unless needed. Context tells you that it usually means the person reading or listening.