naeil ibeul oseul osgeorie georeo dueosseoyo.

Here, 입을 is not the object marker.

It comes from the verb 입다 (to wear) and uses the verb-modifying ending -(으)ㄹ, which describes a noun that follows it.

So:

• 입다 = to wear
• 입을 옷 = the clothes that (someone) will wear

In this sentence, 내일 입을 옷 means:

• the clothes [I will wear tomorrow]
• more naturally: the clothes to wear tomorrow

So the -을 in 입을 is part of the grammar that turns a verb into a noun modifier, not an object particle.

That one is the object particle.

So the sentence contains two different 을 forms:

• 입을: modifier ending from 입다
• 옷을: object marker attached to 옷

Breakdown:

• 내일 입을 옷을
  • 내일 = tomorrow
  • 입을 옷 = clothes to wear
  • 옷을 = marks clothes as the object of the main verb

The main action in the sentence is 걸어 두었어요 (hung up and left ready), so 옷 is the thing that was hung up.

It is a noun phrase built like this:

• 내일 = tomorrow
• 입을 = will wear / to wear
• 옷 = clothes

Korean often places descriptive information before the noun.

So instead of saying:

• the clothes that I will wear tomorrow

Korean says:

• tomorrow wear-will clothes

That is:

• 내일 입을 옷

This is a very common pattern in Korean:

• 먹을 음식 = food to eat / food that one will eat
• 읽을 책 = book to read / book that one will read
• 만날 사람 = person to meet / person one will meet

Because the sentence is talking about a preparation that was already completed.

• 내일 refers to when the clothes will be worn.
• 두었어요 shows that the action of hanging them up happened already.

So the timeline is:

1. I hung the clothes up earlier
2. I plan to wear them tomorrow

That is why the sentence can naturally contain both:

• a future idea: 내일 입을
• a past action: 걸어 두었어요

This is very natural in Korean.

걸어 두었어요 is made from:

• 걸다 = to hang
• -어 두다 = to do something and leave it that way, often for later use, convenience, or preparation
• -었어요 = past polite ending

So 걸어 두었어요 means something like:

• I hung it up and left it there
• I put it on a hanger in advance
• I hung it up ready for later

The important nuance is not just hanging, but hanging it in preparation and leaving it in that state.

Great question. The difference is mainly nuance.

• 걸었어요 = I hung it
  • simple past action
• 걸어 두었어요 = I hung it up and left it ready / left it that way
  • emphasizes preparation or keeping it in that state

In this sentence, 걸어 두었어요 fits well because the speaker is preparing tomorrow’s clothes in advance.

Compare:

• 벽에 그림을 걸었어요.
  • I hung a picture on the wall.
• 내일 입을 옷을 옷걸이에 걸어 두었어요.
  • I hung tomorrow’s clothes on a hanger and left them ready.

에 marks the location or target where something is placed or attached.

So:

• 옷걸이 = hanger
• 옷걸이에 = on the hanger / onto the hanger

With verbs like 걸다 (to hang), 에 is commonly used to show where something is hung:

• 벽에 걸다 = hang on the wall
• 문에 걸다 = hang on the door
• 옷걸이에 걸다 = hang on a hanger

So in this sentence, 옷걸이에 tells you where the clothes were hung.

Yes. 옷걸이 is closely related to 걸다.

• 옷 = clothes
• 걸이 comes from 걸다 and refers to something used for hanging

So 옷걸이 literally means something like:

• clothes-hanger

This is a nice example of how Korean often builds words by combining meaningful parts.

Korean often omits the subject when it is clear from context.

So although the sentence does not explicitly say I, it is usually understood as something like:

• I put tomorrow’s clothes on a hanger
• or I hung up the clothes I’m going to wear tomorrow

The person who will wear the clothes is inferred from context, usually the speaker.

If you wanted to make it explicit, you could say:

• 제가 내일 입을 옷을 옷걸이에 걸어 두었어요.
• 나는 내일 입을 옷을 옷걸이에 걸어 두었어요.

But in everyday Korean, leaving the subject out is very normal.

Yes, technically it could, depending on context.

입을 옷 just means:

• the clothes that will be worn

The subject of 입을 is not stated directly. In many situations, listeners assume it means I will wear because that is the most natural reading here.

But in the right context, it could also mean:

• the clothes my child will wear tomorrow
• the clothes he/she will wear tomorrow

If Korean wants to make that explicit, it can add a subject before the modifier:

• 아이가 내일 입을 옷을 옷걸이에 걸어 두었어요.
  • I hung up the clothes the child will wear tomorrow.

Yes. In speech and informal writing, it is often contracted.

You may see or hear:

• 걸어 두었어요 → full form
• 걸어 뒀어요 → contracted form

Both mean the same thing.

The contracted form is very common in everyday conversation because it sounds more natural and quicker.

Similarly:

• 해 두었어요 → 해 뒀어요
• 넣어 두었어요 → 넣어 뒀어요

So if you hear 걸어 뒀어요, it is the same grammar.

Yes. A helpful way to parse it is:

1. 입을 옷 = clothes to wear
2. 내일 입을 옷 = clothes to wear tomorrow
3. 내일 입을 옷을 옷걸이에 걸어 두었어요 = hung tomorrow’s clothes on a hanger and left them ready

So the core sentence is really:

• 옷을 옷걸이에 걸어 두었어요.
  • I hung the clothes on a hanger and left them there.

And 내일 입을 simply adds extra information about which clothes.

That kind of step-by-step parsing is very useful for long Korean noun phrases.