How to Say "When" in Korean: ~(으)ㄹ 때 Explained

In the previous post, you learned that ~(으)면 can mean "when" for predictable conditions. But Korean has a second, more specific "when" expression: ~(으)ㄹ 때.

Where ~(으)면 focuses on if/when a condition is met, ~(으)ㄹ 때 focuses on the specific time or moment when something happens - past, present, or future.

Once you have both, you can talk about timing with real precision.

What Does ~(으)ㄹ 때 Mean?

~(으)ㄹ 때 means "when" - referring to a specific time, moment, or period when something happens or happened.

한국에 갈 때 꼭 연락하세요. When you go to Korea, be sure to contact me.

어렸을 때 피아노를 배웠어요. When I was young, I learned the piano.

심심할 때 한국어 공부해요. When I'm bored, I study Korean.

How to Form ~(으)ㄹ 때

💡 Same rule as ~(으)ㄹ 거예요 and ~(으)ㄹ 수 있다 - vowel stems add ㄹ, consonant stems add 을, ㄹ stems stay as is.

Conjugation Table

Tense With ~(으)ㄹ 때

This is one of the most important things to get right - and it works differently from English.

In Korean, the tense marker goes on the FINAL verb, not on ~(으)ㄹ 때. But the form of ~(으)ㄹ 때 itself signals whether the "when" moment is happening at the same time as the main action, or before it.

~(으)ㄹ 때 - same time or future

Used when the "when" clause and the main action happen simultaneously, or when referring to a future situation:

밥을 먹을 때 음악을 들어요. When I eat, I listen to music. (same time)

한국에 갈 때 선물을 사 올게요. When I go to Korea, I'll bring back a gift. (future)

~았/었을 때 - before (the action is completed first)

Used when the "when" moment happens after the first action is already completed:

한국에 갔을 때 친구를 만났어요. When I went to Korea, I met a friend. (I arrived first, then met)

숙제를 끝냈을 때 연락할게요. I'll contact you when I've finished my homework. (finish first, then contact)

💡 Quick guide:

• Same time happening → ~(으)ㄹ 때
• First action completed, then second → ~았/었을 때

~(으)ㄹ 때 for Past Situations: 어렸을 때

One of the most common uses of ~(으)ㄹ 때 is talking about past periods of your life:

💡 이다 (to be) + ㄹ 때: 학생이다 → 학생일 때 (when [I] was a student) No (으) needed after 이다 - just 일 때.

~(으)ㄹ 때 in Real Sentences

😴 Habits & Routines

심심할 때 보통 뭐 해요?

• Natural: What do you usually do when you're bored?

피곤할 때 커피를 마셔요.

• Natural: When I'm tired, I drink coffee.

운동할 때 음악을 들어요.

• Natural: When I exercise, I listen to music.

요리할 때 유튜브를 봐요.

• Natural: When I cook, I watch YouTube.

출퇴근할 때 한국어 팟캐스트를 들어요.

• Natural: When commuting, I listen to Korean podcasts.

🌧️ Conditions & Situations

비가 올 때 우산을 가져오세요.

• Natural: When it rains, bring an umbrella.

모를 때 물어보면 돼요.

• Natural: When you don't know, you can ask.

힘들 때 친구한테 얘기해요.

• Natural: When it's hard, I talk to a friend.

배가 고플 때 기분이 안 좋아요.

• Natural: When I'm hungry, I'm in a bad mood.

📍 Specific Past Moments

처음 한국어를 배웠을 때 정말 어려웠어요.

• Natural: When I first learned Korean, it was really difficult.

서울에 갔을 때 경복궁에 가봤어요.

• Natural: When I went to Seoul, I visited Gyeongbokgung.

그 말을 들었을 때 너무 기뻤어요.

• Natural: When I heard that, I was so happy.

처음 만났을 때 뭐 느꼈어요?

• Natural: What did you feel when you first met?

~(으)ㄹ 때 vs ~(으)면 - The Full Comparison

Same idea, different patterns:

한국에 가면 꼭 연락하세요. (If/when you go to Korea, be sure to contact me - condition)

한국에 갈 때 선물 사다 줄게요. (When you go to Korea, I'll buy you a gift - specific moment of going)

Both are natural - but the emphasis differs slightly. ~(으)면 feels more conditional; ~(으)ㄹ 때 feels more like "at that specific time."

Useful Fixed Expressions With ~(으)ㄹ 때

그럴 때 is especially useful:

그럴 때 어떻게 해요? What do you do in a situation like that?

그럴 때는 쉬는 게 좋아요. In a situation like that, it's best to rest.

Real Conversations Using ~(으)ㄹ 때

📍 Conversation 1: Talking about habits

A: 스트레스 받을 때 보통 뭐 해요? (What do you usually do when you're stressed?)

B: 음악을 들어요. 아니면 밖에 나가서 걸어요. (I listen to music. Or I go outside and walk.)

A: 저는 요리할 때 스트레스가 풀려요. (For me, stress gets relieved when I cook.)

B: 그렇군요! 맛있는 거 만들 때 기분이 좋아지겠어요. (I see! You must feel better when you make something delicious.)

📍 Conversation 2: Sharing memories

A: 어렸을 때 꿈이 뭐였어요? (What was your dream when you were young?)

B: 선생님이 되고 싶었어요. 학생일 때 선생님을 정말 좋아했거든요. (I wanted to become a teacher. When I was a student, I really liked my teachers.)

A: 처음 한국어를 배웠을 때는 어땠어요? (What was it like when you first learned Korean?)

B: 한글을 처음 읽었을 때 정말 신기했어요! (When I first read Hangul, it was really amazing!)

📍 Conversation 3: Making plans

A: 시간 있을 때 같이 밥 먹어요. (When you have time, let's eat together.)

B: 좋아요! 이번 주는 바쁜데 다음 주에 시간이 생길 것 같아요. (Sounds good! This week I'm busy, but I think I'll have time next week.)

A: 그럼 다음 주에 시간 될 때 연락해요. (Then contact me when you're free next week.)

B: 네, 확정되면 바로 연락할게요. (Yes, I'll contact you right away when it's confirmed.)

Common Mistakes to Avoid

❌ Mistake 1: Using past tense ~았/었 in ~(으)ㄹ 때 for simultaneous actions

❌ 밥을 먹었을 때 음악을 들어요. (simultaneous - wrong tense) ✅ 밥을 먹을 때 음악을 들어요.

Use ~았/었을 때 only when the first action is completed before the second.

❌ Mistake 2: Forgetting 을 after consonant stems

❌ 먹 때 ✅ 먹을 때

❌ Mistake 3: Using ~(으)ㄹ 때 where ~(으)면 fits better

시간이 있을 때 오세요. (Come when you have time - specific moment) ✅ 시간이 있으면 오세요. (Come if you have time - conditional) ✅

Both can work - but if you're emphasizing "at that specific time," use ~(으)ㄹ 때.

Quick Practice

Form ~(으)ㄹ 때 sentences:

1. 피곤하다 + 커피를 마셔요. (When tired, I drink coffee.)
2. 한국에 가다 + 뭐 하고 싶어요? (What do you want to do when you go to Korea?)
3. 어리다 + 뭐가 되고 싶었어요? (What did you want to become when you were young?)
4. 모르다 + 사전을 찾아봐요. (When I don't know, I look it up in the dictionary.)
5. 숙제가 끝나다 + 게임할 거예요. (When homework is done, I'll play games.)

Answers:

1. 피곤할 때 커피를 마셔요.
2. 한국에 갈 때 뭐 하고 싶어요?
3. 어렸을 때 뭐가 되고 싶었어요?
4. 모를 때 사전을 찾아봐요.
5. 숙제가 끝났을 때 게임할 거예요.

Summary

~(으)ㄹ 때 and ~(으)면 together give you complete control over "when" and "if" in Korean. With both in your toolkit, you can talk about habits, memories, plans, and conditions with the kind of precision that makes Korean feel truly natural.