~아 놓다 vs ~아 두다 vs ~아 있다

How are they different “~아/어 놓다, ~아/어 두다, ~고 있다 and ~아/어 있다”?

🔎 1. -아/어 놓다 — “do something on purpose and leave it that way”

This pattern emphasizes that the action was intentionally done, and its resulting state is kept for a reason—convenience, preparation, or habit.
The focus is on purposeful preparation.

✔ English nuance

“I did it (on purpose) and left it like that.”

✔ Examples

❗ Daily life

• 문을 열어 놓았어요.
  I opened the door and left it open on purpose.

• 불을 켜 놓고 잤어요.
  I turned the light on and slept with it on.

❗ Preparation

• 손님이 올 거라서 과자를 미리 사 놓았어요.
  I bought snacks beforehand and have them ready because guests are going to come.

❗ Reminder / habit

• 중요한 문서는 파일에 넣어 두세요.
  Put the important documents in a file and leave them there.

🔎 2. -아/어 두다 — “do something and keep it that way for later benefit”

Very similar to -아/어 놓다, but more emphasis on longer-term benefit, preparation, convenience, or preventive action.
Often used in instructions, planning, or when something is done in advance.

✔ English nuance

“I did it and kept it that way for future use or benefit.”

✔ Examples

❗ Preparation for later

• 환기를 하려고 창문을 열어 두었어요.
  I opened the window and kept it open so the room can ventilate.

• 내일 아침에 먹으려고 샌드위치를 만들어 두었어요.
  I made Sandwich and kept it for tomorrow morning.

❗ Long-term helpful state

• Sohyun.One 비밀번호를 잊지 않게 메모해 두었어요.
  I wrote it down so I won’t forget the password of Sohyun.One later.

• 여행 가기 전에 짐을 미리 싸 두었어요.
  I packed my bags in advance for the trip.

• 문서를 백업해 두세요.
  Please back up the files and keep them saved.

🔎 3. -고 있다 — “an action is currently in progress”

This expresses an action that is happening right now, ongoing, or repeated in a continuous way.

✔ English nuance

“I am doing this now.” / “This action is happening.”

✔ Examples

❗ Right now

• 문을 열고 있어요.
  I am (in the process of) opening the door.

• 정현 씨가 비빔밥을 먹고 있어요.
  Junghyun is eating Bibimbap.

• 멜 씨는 소현 씨를 기다리고 있어요.
  Mel is waiting for Sohyun.

❗ Ongoing repeated action

• 요즘 한국어를 배우고 있어요.
  I’m learning Korean these days.

🔎 4. -아/어 있다 — “the result of an action remains”

This expresses a static state that was caused by a past action.
The action itself is already finished; now we focus on the current condition.

✔ English nuance

“It is in the state of being (verb-ed).”
“The action is done, and the result remains.”

✔ Examples

❗ States of objects

• 문이 열려 있어요.
  The door is open (it remains open).

• 불이 켜져 있어요.
  The light is on.

❗ Clothing / things worn

• 모자가 벗겨져 있어요.
  His hat is (in the state of being) taken off.

• 창문에 커튼이 쳐져 있어요.
  The curtains are drawn on the window.

❗ Situations

• 한강 다리에 차가 많이 서 있어요.
  Cars are (in the state of being) stopped on the Han-river bridge.

📌 Quick Comparison Summary

Pattern

Focus

English meaning

Example

-아/어 놓다

intentional action + leaving it

“did it on purpose and left it like that”

창문을 열어 놓았어요.

-아/어 두다

preparation /

future benefit

“did it and kept it for later advantage”

물을 데워 두었어요.

-고 있다

action in progress

“am doing (right now)”

문을 열고 있어요.

-아/어 있다

resultative state

“is in the state of being (verb-ed)”

문이 열려 있어요.