⏱️

At the same time: -(으)ㅁ과 동시에

Agent Progress
Built
Build Order
102
Keywords
동시
Lesson #
S
Done
Section
Advanced Grammar
🎯
TL;DR 🦄
  • ⏱️ -(으)ㅁ과 동시에 [-eu-m-gwa dong-si-e] means at the same time as / simultaneously with / the very moment that.
  • 📋 It is formal and written. It turns the first action or state into a compact fact with -(으)ㅁ, then adds 과 동시에 [gwa dong-si-e] — “and at the same time.”
  • 🧭 Use it for polished explanations, reports, essays, news-style writing, announcements, and formal descriptions where two things happen together or one thing immediately triggers another.
🔊
🎧 Iru Helper Note — Use
Korean Helper Widgets
Korean Helper Widgets to hear long formal chunks like 도착함과 동시에 [do-cha-kam-gwa dong-si-e] (at the same time as arriving), 발표됨과 동시에 [bal-pyo-doem-gwa dong-si-e] (as soon as it is announced), and 시작됨과 동시에 [si-jak-doem-gwa dong-si-e] (at the same time as it begins). Your ears deserve snacks. 🎧🍪
 

🌈 The Big Picture

동시 [dong-si] means “same time / simultaneity.” Add 에 [e] (“at/to”) and you get 동시에 [dong-si-e] — “at the same time / simultaneously.” ⏱️
The advanced pattern -(으)ㅁ과 동시에 is built from two pieces:
  • -(으)ㅁ [-eu-m / -m] — a formal noun-like fact ending, as in 시작됨 [si-jak-doem] “the fact of beginning / being started.”
  • 과 동시에 [gwa dong-si-e] — “and at the same time.”
So 시작됨과 동시에 means “at the same time as it begins / immediately upon beginning.” It feels polished, compact, and report-ready — basically Korean wearing a blazer. 🧥
Everyday Korean often uses lighter forms like -자마자 [-ja-ma-ja] (as soon as), -(으)면서 [-eu-myeon-seo] (while doing), or -는 동시에 [-neun dong-si-e] (while also / at the same time). This lesson focuses on the more formal -(으)ㅁ과 동시에. 📋

🎨 The Core -(으)ㅁ과 동시에 Family

1. Vowel-ending action/state stem + ㅁ과 동시에

Use -ㅁ과 동시에 after stems ending in a vowel.
  • 시작되다 [si-jak-doe-da] = to begin / to be started → 시작됨과 동시에 [si-jak-doem-gwa dong-si-e] — at the same time as it begins 🚦
  • 공개되다 [gong-gae-doe-da] = to be released / made public → 공개됨과 동시에 [gong-gae-doem-gwa dong-si-e] — as soon as it is released 📢
  • 도착하다 [do-chak-ha-da] = to arrive → 도착함과 동시에 [do-cha-kam-gwa dong-si-e] — immediately upon arriving 🚉

2. Consonant-ending action/state stem + 음과 동시에

Use -음과 동시에 after most consonant-ending stems.
  • 끝나다 [kkeut-na-da] = to end uses a vowel-ending stem, so it becomes 끝남과 동시에 [kkeut-nam-gwa dong-si-e] — as soon as it ends 🏁
  • 열리다 [yeol-li-da] = to open / be held uses a vowel-ending stem, so it becomes 열림과 동시에 [yeol-lim-gwa dong-si-e] — as soon as it opens 🚪
  • 받다 [bat-da] = to receive → 받음과 동시에 [ba-deum-gwa dong-si-e] — at the same time as receiving 📩
  • 읽다 [ik-da] = to read → 읽음과 동시에 [il-geum-gwa dong-si-e] — at the same time as reading 📖

3. Noun + 과 동시에

When the first part is already a noun event or role, attach 과 동시에 directly.
  • 출발 [chul-bal] = departure → 출발과 동시에 [chul-bal-gwa dong-si-e] — at the same time as departure 🚆
  • 발표 [bal-pyo] = announcement/presentation → 발표와 동시에 [bal-pyo-wa dong-si-e] — at the same time as the announcement 🎤
  • 입장 [ip-jang] = entry/entrance → 입장과 동시에 [ip-jang-gwa dong-si-e] — upon entry 🎟️
Use 와 동시에 after a noun ending in a vowel, and 과 동시에 after a noun ending in a consonant.

🛠️ How They Work in a Sentence

  1. 회의가 시작됨과 동시에 자료가 공유됐어요.
      2. [hoe-ui-ga si-jak-doem-gwa dong-si-e ja-ryo-ga gong-yu-dwae-sseo-yo]
      As soon as the meeting began, the materials were shared. 📝📂
      회의 = meeting, 자료 = materials, 공유되다 = to be shared.
  1. 기차가 도착함과 동시에 승객들이 내렸어요.
      2. [gi-cha-ga do-cha-kam-gwa dong-si-e seung-gaek-deu-ri nae-ryeo-sseo-yo]
      As soon as the train arrived, the passengers got off. 🚆🚶
      기차 = train, 승객 = passenger, 내리다 = to get off.
  1. 새 정책이 발표됨과 동시에 문의가 늘었어요.
      2. [sae jeong-chae-gi bal-pyo-doem-gwa dong-si-e mun-ui-ga neu-reo-sseo-yo]
      As soon as the new policy was announced, inquiries increased. 📢📈
      정책 = policy, 문의 = inquiry, 늘다 = to increase.

🧩 General Formation Rule

Verb/adjective stem + -(으)ㅁ과 동시에

  • Vowel-ending stem → -ㅁ과 동시에
    • 도착하다 → 도착함과 동시에 — as soon as one arrives 🚉
    • 공개되다 → 공개됨과 동시에 — as soon as it is released 📢
    • 끝나다 → 끝남과 동시에 — as soon as it ends 🏁
  • Consonant-ending stem → -음과 동시에
    • 받다 → 받음과 동시에 — upon receiving 📩
    • 읽다 → 읽음과 동시에 — while/at the same time as reading 📖
    • 닫다 → 닫음과 동시에 — at the same time as closing 🚪

Noun + 과/와 동시에

  • consonant-ending noun → 과 동시에
    • 출발과 동시에 — at the same time as departure 🚆
    • 입장과 동시에 — upon entry 🎟️
  • vowel-ending noun → 와 동시에
    • 발표와 동시에 — at the same time as the announcement 🎤
    • 완료와 동시에 — at the same time as completion ✅

When it implies “immediately”

This pattern often means more than simple overlap. In sentences like 문이 열림과 동시에 사람들이 들어왔어요 [mu-ni yeol-lim-gwa dong-si-e sa-ram-deu-ri deu-reo-wa-sseo-yo] — “As soon as the door opened, people came in” — it can feel like the second event happened immediately when the first event happened. 🚪

📚 Cross-check note

The meaning of 동시에 as “at the same time,” the formal nominalizing role of -(으)ㅁ, and the related expression -는 동시에 were checked against korean.go.kr and the National Institute of Korean Language dictionary resources. ✅

🪞 Synonym Alert

  • -(으)ㅁ과 동시에 — formal/written “at the same time as / immediately upon” 📋
  • -는 동시에 — at the same time as / while also; less noun-like and very common in explanations 🧭
  • -(으)면서 — while doing; same subject often performs both actions 🚶🎧
  • -자마자 — as soon as; emphasizes immediate sequence ⚡
  • 동시에 — simultaneously / at the same time; can stand as an adverb ⏱️

⚠️ Pitfalls to Dodge

  • ❌ 도착하과 동시에 → ✅ 도착함과 동시에. Use the formal noun form -ㅁ after 하다-verbs. 🚉
  • ❌ 받ㅁ과 동시에 → ✅ 받음과 동시에. Consonant-ending stems need -음. 📩
  • ❌ 발표과 동시에 → ✅ 발표와 동시에. Vowel-ending nouns use 와, not 과. 🎤
  • ❌ Using -(으)ㅁ과 동시에 for casual everyday chatter → ✅ Use it mainly in formal writing, news-style explanations, reports, and polished speech. 🧥
  • ❌ Treating it exactly like -(으)면서 every time → ✅ -(으)ㅁ과 동시에 can mark immediate timing between two events, not just one person doing two actions together. ⚡
🎉 Bottom line: -(으)ㅁ과 동시에 is your formal “same-time switch.” One event happens, and boom — another event begins, changes, or appears at that exact moment. ⏱️✨
 
Try this exercise
Instructions: Complete each prompt with the correct -(으)ㅁ과 동시에 or noun + 과/와 동시에 form. Say the full sentence aloud, then open the Answer toggle. ⏱️
1. 회의가 시작되＿＿＿＿ 자료가 공유됐어요.
[hoe-ui-ga si-jak-doe＿＿＿＿ ja-ryo-ga gong-yu-dwae-sseo-yo]
As soon as the meeting began, the materials were shared. 📝📂
Answer
ㅁ과 동시에 — 시작되다 → 시작됨과 동시에. Vowel-ending stem + -ㅁ과 동시에.
2. 문이 열리＿＿＿＿ 사람들이 들어왔어요.
[mu-ni yeol-li＿＿＿＿ sa-ram-deu-ri deu-reo-wa-sseo-yo]
As soon as the door opened, people came in. 🚪
Answer
ㅁ과 동시에 — 열리다 → 열림과 동시에.
3. 기차가 도착하＿＿＿＿ 승객들이 내렸어요.
[gi-cha-ga do-chak-ha＿＿＿＿ seung-gaek-deu-ri nae-ryeo-sseo-yo]
As soon as the train arrived, the passengers got off. 🚆
Answer
ㅁ과 동시에 — 도착하다 → 도착함과 동시에.
4. 안내문을 받＿＿＿＿ 내용을 확인했어요.
[an-nae-mu-neul bat＿＿＿＿ nae-yong-eul hwa-gin-hae-sseo-yo]
At the same time as receiving the notice, I checked the content. 📩
Answer
음과 동시에 — 받다 → 받음과 동시에. Consonant-ending stem + -음과 동시에.
5. 책을 읽＿＿＿＿ 중요한 표현을 표시했어요.
[chae-geul ik＿＿＿＿ jung-yo-han pyo-hyeo-neul pyo-si-hae-sseo-yo]
While reading the book, I marked important expressions. 📖✍️
Answer
음과 동시에 — 읽다 → 읽음과 동시에.
6. 출발＿＿＿＿ 안내 방송이 나왔어요.
[chul-bal＿＿＿＿ an-nae bang-song-i na-wa-sseo-yo]
At the same time as departure, an announcement came on. 🚆📢
Answer
과 동시에 — 출발 ends in a consonant, so use 과 동시에.
7. 발표＿＿＿＿ 문의가 늘었어요.
[bal-pyo＿＿＿＿ mun-ui-ga neu-reo-sseo-yo]
At the same time as the announcement, inquiries increased. 🎤📈
Answer
와 동시에 — 발표 ends in a vowel, so use 와 동시에.
8. 수업이 끝나＿＿＿＿ 학생들이 질문했어요.
[su-eo-bi kkeut-na＿＿＿＿ hak-saeng-deu-ri jil-mun-hae-sseo-yo]
As soon as class ended, the students asked questions. 🏫🙋
Answer
ㅁ과 동시에 — 끝나다 → 끝남과 동시에.
9. 신청이 완료되＿＿＿＿ 확인 문자가 왔어요.
[sin-cheong-i wan-nyo-doe＿＿＿＿ hwa-gin mun-ja-ga wa-sseo-yo]
As soon as the application was completed, a confirmation text came. ✅📱
Answer
ㅁ과 동시에 — 완료되다 → 완료됨과 동시에.
10. 입장＿＿＿＿ 표를 확인했어요.
[ip-jang＿＿＿＿ pyo-reul hwa-gin-hae-sseo-yo]
Upon entry, I checked the ticket. 🎟️
Answer
과 동시에 — 입장 ends in a consonant, so use 과 동시에.
📚
Vocabulary Box
  • 회의 → meeting
  • 시작되다 → to begin / be started
  • 자료 → materials
  • 공유되다 → to be shared
  • 문 → door
  • 열리다 → to open / be opened
  • 사람 → person
  • 들어오다 → to come in
  • 기차 → train
  • 도착하다 → to arrive
  • 승객 → passenger
  • 내리다 → to get off
  • 안내문 → notice
  • 받다 → to receive
  • 내용 → content
  • 확인하다 → to check / confirm
  • 책 → book
  • 읽다 → to read
  • 표현 → expression
  • 표시하다 → to mark
  • 출발 → departure
  • 방송 → broadcast / announcement
  • 발표 → announcement / presentation
  • 문의 → inquiry
  • 늘다 → to increase
  • 수업 → class
  • 끝나다 → to end
  • 학생 → student
  • 질문하다 → to ask a question
  • 신청 → application
  • 완료되다 → to be completed
  • 문자 → text message
  • 입장 → entry
  • 표 → ticket
Memory tips 💡
  • Verb/adjective stem → make -(으)ㅁ first.
  • Noun ending in consonant → 과 동시에.
  • Noun ending in vowel → 와 동시에.
🚀
Want more reps? The Practice Hub below gives you a full same-time grammar workout. ⏱️
 
📦
🎯 Practice Hub — At the same time: -(으)ㅁ과 동시에
 
Welcome to the simultaneity control room. ⏱️ You’ll practice making formal “same-time” links with -(으)ㅁ과 동시에, choosing 과 vs. 와, and spotting when the pattern means “right as that happened.” Tiny grammar switch, big timing energy. ⚡
 
🔊 Audio reminder: Use
Korean Helper Widgets
Korean Helper Widgets when you want to hear a completed sentence aloud.
 
📝 Instructions: Fill each blank, read the full Korean sentence aloud, then open the Answer toggle. Watch whether the first part is a verb/adjective stem or an already-made noun.
 

Exercise 1 — Build the Formal Same-Time Form 🧱

A. 시작되다 → 시작되＿＿＿＿ 동시에
[si-jak-doe-da → si-jak-doe＿＿＿＿ dong-si-e]
to begin → at the same time as beginning 🚦
Answer
ㅁ과 — 시작됨과 동시에. Vowel-ending stem + -ㅁ과 동시에.
B. 공개되다 → 공개되＿＿＿＿ 동시에
[gong-gae-doe-da → gong-gae-doe＿＿＿＿ dong-si-e]
to be released → as soon as it is released 📢
Answer
ㅁ과 — 공개됨과 동시에.
C. 도착하다 → 도착하＿＿＿＿ 동시에
[do-chak-ha-da → do-chak-ha＿＿＿＿ dong-si-e]
to arrive → immediately upon arriving 🚉
Answer
ㅁ과 — 도착함과 동시에.
D. 끝나다 → 끝나＿＿＿＿ 동시에
[kkeut-na-da → kkeut-na＿＿＿＿ dong-si-e]
to end → as soon as it ends 🏁
Answer
ㅁ과 — 끝남과 동시에.
E. 열리다 → 열리＿＿＿＿ 동시에
[yeol-li-da → yeol-li＿＿＿＿ dong-si-e]
to open / be held → as soon as it opens 🚪
Answer
ㅁ과 — 열림과 동시에.
F. 받다 → 받＿＿＿＿ 동시에
[bat-da → bat＿＿＿＿ dong-si-e]
to receive → at the same time as receiving 📩
Answer
음과 — 받음과 동시에. Consonant-ending stem + -음과 동시에.
G. 읽다 → 읽＿＿＿＿ 동시에
[ik-da → ik＿＿＿＿ dong-si-e]
to read → at the same time as reading 📖
Answer
음과 — 읽음과 동시에.
H. 닫다 → 닫＿＿＿＿ 동시에
[dat-da → dat＿＿＿＿ dong-si-e]
to close → at the same time as closing 🚪
Answer
음과 — 닫음과 동시에.
I. 공유되다 → 공유되＿＿＿＿ 동시에
[gong-yu-doe-da → gong-yu-doe＿＿＿＿ dong-si-e]
to be shared → as soon as it is shared 📂
Answer
ㅁ과 — 공유됨과 동시에.
J. 완료되다 → 완료되＿＿＿＿ 동시에
[wan-nyo-doe-da → wan-nyo-doe＿＿＿＿ dong-si-e]
to be completed → upon completion ✅
Answer
ㅁ과 — 완료됨과 동시에.
📚
Vocabulary Box
  • 시작되다 → to begin / be started
  • 공개되다 → to be released / made public
  • 도착하다 → to arrive
  • 끝나다 → to end
  • 열리다 → to open / be held
  • 받다 → to receive
  • 읽다 → to read
  • 닫다 → to close
  • 공유되다 → to be shared
  • 완료되다 → to be completed
  • 동시에 → at the same time
Tip 💡 First make the formal noun: 시작됨, 받음, 읽음. Then add 과 동시에.
 

Exercise 2 — Event Timing Sentences ⚡

A. 문이 열＿＿＿＿ 사람들이 들어왔어요.
[mu-ni yeol＿＿＿＿ sa-ram-deu-ri deu-reo-wa-sseo-yo]
As soon as the door opened, people came in. 🚪
Answer
림과 동시에 — 문이 열림과 동시에 사람들이 들어왔어요.
B. 기차가 도착＿＿＿＿ 승객들이 내렸어요.
[gi-cha-ga do-chak＿＿＿＿ seung-gaek-deu-ri nae-ryeo-sseo-yo]
As soon as the train arrived, passengers got off. 🚆
Answer
함과 동시에 — 도착함과 동시에.
C. 회의가 시작＿＿＿＿ 자료가 공유됐어요.
[hoe-ui-ga si-jak＿＿＿＿ ja-ryo-ga gong-yu-dwae-sseo-yo]
As soon as the meeting began, the materials were shared. 📝
Answer
됨과 동시에 — 시작됨과 동시에.
D. 수업이 끝＿＿＿＿ 학생들이 질문했어요.
[su-eo-bi kkeut＿＿＿＿ hak-saeng-deu-ri jil-mun-hae-sseo-yo]
As soon as class ended, students asked questions. 🏫
Answer
남과 동시에 — 끝남과 동시에.
E. 신청이 완료＿＿＿＿ 확인 문자가 왔어요.
[sin-cheong-i wan-nyo＿＿＿＿ hwa-gin mun-ja-ga wa-sseo-yo]
As soon as the application was completed, a confirmation text came. 📱
Answer
됨과 동시에 — 완료됨과 동시에.
F. 새 정책이 발표＿＿＿＿ 문의가 늘었어요.
[sae jeong-chae-gi bal-pyo＿＿＿＿ mun-ui-ga neu-reo-sseo-yo]
As soon as the new policy was announced, inquiries increased. 📢
Answer
됨과 동시에 — 발표됨과 동시에.
G. 자료가 공개＿＿＿＿ 댓글이 달렸어요.
[ja-ryo-ga gong-gae＿＿＿＿ daet-geu-ri dal-lyeo-sseo-yo]
As soon as the materials were released, comments were posted. 💬
Answer
됨과 동시에 — 공개됨과 동시에.
H. 창이 닫＿＿＿＿ 알림이 사라졌어요.
[chang-i dat＿＿＿＿ al-li-mi sa-ra-jyeo-sseo-yo]
As soon as the window closed, the notification disappeared. 🪟
Answer
음과 동시에 — 닫음과 동시에.
I. 안내문을 받＿＿＿＿ 내용을 확인했어요.
[an-nae-mu-neul bat＿＿＿＿ nae-yong-eul hwa-gin-hae-sseo-yo]
At the same time as receiving the notice, I checked the content. 📩
Answer
음과 동시에 — 받음과 동시에.
J. 책을 읽＿＿＿＿ 표현을 표시했어요.
[chae-geul ik＿＿＿＿ pyo-hyeo-neul pyo-si-hae-sseo-yo]
While reading the book, I marked expressions. 📖
Answer
음과 동시에 — 읽음과 동시에.
📚
Vocabulary Box
  • 문 → door
  • 열리다 → to open / be opened
  • 사람 → person
  • 들어오다 → to come in
  • 기차 → train
  • 승객 → passenger
  • 내리다 → to get off
  • 회의 → meeting
  • 자료 → materials
  • 수업 → class
  • 학생 → student
  • 신청 → application
  • 문자 → text message
  • 정책 → policy
  • 문의 → inquiry
  • 댓글 → comment
  • 창 → window
  • 알림 → notification
  • 안내문 → notice
  • 내용 → content
  • 책 → book
  • 표현 → expression
Tip 💡 In timing sentences, this pattern often feels like “right when / immediately upon.”
 

Exercise 3 — Noun + 과/와 동시에 🎟️

A. 출발＿＿＿＿ 안내 방송이 나왔어요.
[chul-bal＿＿＿＿ an-nae bang-song-i na-wa-sseo-yo]
At departure, an announcement came on. 🚆
Answer
과 동시에 — 출발 ends in a consonant.
B. 발표＿＿＿＿ 문의가 늘었어요.
[bal-pyo＿＿＿＿ mun-ui-ga neu-reo-sseo-yo]
At the same time as the announcement, inquiries increased. 🎤
Answer
와 동시에 — 발표 ends in a vowel.
C. 입장＿＿＿＿ 표를 확인했어요.
[ip-jang＿＿＿＿ pyo-reul hwa-gin-hae-sseo-yo]
Upon entry, I checked the ticket. 🎟️
Answer
과 동시에.
D. 완료＿＿＿＿ 알림이 왔어요.
[wan-nyo＿＿＿＿ al-li-mi wa-sseo-yo]
At completion, a notification came. ✅
Answer
와 동시에.
E. 시작＿＿＿＿ 화면이 바뀌었어요.
[si-jak＿＿＿＿ hwa-myeo-ni ba-kkwi-eo-sseo-yo]
At the start, the screen changed. 🖥️
Answer
과 동시에.
F. 공개＿＿＿＿ 반응이 나왔어요.
[gong-gae＿＿＿＿ ban-eung-i na-wa-sseo-yo]
At the release, reactions came out. 📢
Answer
와 동시에.
G. 도착＿＿＿＿ 메시지를 보냈어요.
[do-chak＿＿＿＿ me-si-ji-reul bo-nae-sseo-yo]
Upon arrival, I sent a message. 🚉
Answer
과 동시에.
H. 퇴장＿＿＿＿ 문이 닫혔어요.
[toe-jang＿＿＿＿ mu-ni da-chyeo-sseo-yo]
At exit, the door closed. 🚪
Answer
과 동시에.
I. 공유＿＿＿＿ 수정 요청이 왔어요.
[gong-yu＿＿＿＿ su-jeong yo-cheong-i wa-sseo-yo]
At the same time as sharing, a revision request came. 📂
Answer
와 동시에.
J. 확인＿＿＿＿ 기록을 남겼어요.
[hwa-gin＿＿＿＿ gi-ro-geul nam-gyeo-sseo-yo]
At confirmation, I left a record. 🧾
Answer
과 동시에.
📚
Vocabulary Box
  • 출발 → departure
  • 안내 방송 → announcement broadcast
  • 발표 → announcement / presentation
  • 문의 → inquiry
  • 입장 → entry
  • 표 → ticket
  • 완료 → completion
  • 알림 → notification
  • 시작 → start
  • 화면 → screen
  • 공개 → release / public opening
  • 반응 → reaction
  • 도착 → arrival
  • 메시지 → message
  • 퇴장 → exit
  • 문 → door
  • 공유 → sharing
  • 수정 요청 → revision request
  • 확인 → confirmation
  • 기록 → record
Tip 💡 Noun + 과/와 동시에: consonant takes 과, vowel takes 와.
 

Exercise 4 — Choose the Best Same-Time Expression 🧭

A. Formal: 회의가 시작＿＿＿＿ 자료가 공유됐어요.
[hoe-ui-ga si-jak＿＿＿＿ ja-ryo-ga gong-yu-dwae-sseo-yo]
As soon as the meeting began, materials were shared. 📝
Answer
됨과 동시에 — formal timing: 시작됨과 동시에.
B. Lighter explanation: 회의가 시작되는 동시에 자료가 공유됐어요.
[hoe-ui-ga si-jak-doe-neun dong-si-e ja-ryo-ga gong-yu-dwae-sseo-yo]
The meeting began and the materials were shared at the same time. 📝
Answer
-는 동시에 is also possible and less noun-like than -(으)ㅁ과 동시에.
C. Immediate sequence: 문이 열리자마자 사람들이 들어왔어요.
[mu-ni yeol-li-ja-ma-ja sa-ram-deu-ri deu-reo-wa-sseo-yo]
As soon as the door opened, people came in. 🚪
Answer
-자마자 emphasizes “as soon as.” 열림과 동시에 would sound more formal.
D. Same subject: 책을 읽으면서 표현을 표시했어요.
[chae-geul il-geu-myeon-seo pyo-hyeo-neul pyo-si-hae-sseo-yo]
I marked expressions while reading the book. 📖
Answer
-(으)면서 is natural when the same person does two actions together.
E. Formal version: 책을 읽＿＿＿＿ 표현을 표시했어요.
[chae-geul ik＿＿＿＿ pyo-hyeo-neul pyo-si-hae-sseo-yo]
At the same time as reading the book, I marked expressions. ✍️
Answer
음과 동시에 — 읽음과 동시에.
F. Spoken quick timing: 도착하자마자 메시지를 보냈어요.
[do-cha-ka-ja-ma-ja me-si-ji-reul bo-nae-sseo-yo]
As soon as I arrived, I sent a message. 📱
Answer
-자마자 is common for immediate spoken sequence.
G. Formal quick timing: 도착＿＿＿＿ 메시지를 보냈어요.
[do-chak＿＿＿＿ me-si-ji-reul bo-nae-sseo-yo]
Immediately upon arrival, I sent a message. 🚉
Answer
함과 동시에 — 도착함과 동시에.
H. Adverb only: 두 작업이 동시에 진행됐어요.
[du jak-eo-bi dong-si-e jin-haeng-dwae-sseo-yo]
The two tasks proceeded simultaneously. 🛠️
Answer
동시에 alone works as an adverb meaning “simultaneously.”
I. Formal noun event: 발표＿＿＿＿ 문의가 늘었어요.
[bal-pyo＿＿＿＿ mun-ui-ga neu-reo-sseo-yo]
At the same time as the announcement, inquiries increased. 🎤
Answer
와 동시에 — noun ending in vowel.
J. Formal verb event: 발표되＿＿＿＿ 문의가 늘었어요.
[bal-pyo-doe＿＿＿＿ mun-ui-ga neu-reo-sseo-yo]
As soon as it was announced, inquiries increased. 📢
Answer
ㅁ과 동시에 — 발표됨과 동시에.
📚
Vocabulary Box
  • 회의 → meeting
  • 시작되다 → to begin / be started
  • 자료 → materials
  • 문 → door
  • 사람 → person
  • 책 → book
  • 읽다 → to read
  • 표현 → expression
  • 도착하다 → to arrive
  • 메시지 → message
  • 작업 → task
  • 진행되다 → to proceed
  • 발표 → announcement / presentation
  • 발표되다 → to be announced
  • 문의 → inquiry
  • 늘다 → to increase
Tip 💡 Use -(으)ㅁ과 동시에 for a formal, noun-like timing link; use -자마자 for plain “as soon as.”
 

Exercise 5 — Mixed Mastery + Pitfall Patrol 🛡️

A. Fix: ❌ 도착하과 동시에
[do-chak-ha-gwa dong-si-e]
at the same time as arriving 🚉
Answer
✅ 도착함과 동시에 — 하다-verbs use 함과 동시에.
B. Fix: ❌ 받ㅁ과 동시에
[bat-m-gwa dong-si-e]
at the same time as receiving 📩
Answer
✅ 받음과 동시에 — consonant-ending stem + -음과 동시에.
C. Fix: ❌ 발표과 동시에
[bal-pyo-gwa dong-si-e]
at the same time as the announcement 🎤
Answer
✅ 발표와 동시에 — 발표 ends in a vowel, so use 와.
D. Fix: ❌ 읽ㅁ과 동시에
[ik-m-gwa dong-si-e]
at the same time as reading 📖
Answer
✅ 읽음과 동시에 — consonant-ending stem + -음과 동시에.
E. Choose the formal written form: 시작됨과 동시에 / 시작되는 동시에
[si-jak-doem-gwa dong-si-e / si-jak-doe-neun dong-si-e]
at the same time as it begins 🚦
Answer
시작됨과 동시에 — more formal and noun-like.
F. Choose the noun form: 출발과 동시에 / 출발함과 동시에
[chul-bal-gwa dong-si-e / chul-bal-ham-gwa dong-si-e]
at the same time as departure 🚆
Answer
출발과 동시에 — 출발 is already a noun event.
G. Translate: “As soon as the door opened, people came in.”
Answer
문이 열림과 동시에 사람들이 들어왔어요. [mu-ni yeol-lim-gwa dong-si-e sa-ram-deu-ri deu-reo-wa-sseo-yo]
H. Translate: “At the same time as the release, reactions came out.”
Answer
공개와 동시에 반응이 나왔어요. [gong-gae-wa dong-si-e ban-eung-i na-wa-sseo-yo]
I. Translate: “As soon as the application was completed, a text message came.”
Answer
신청이 완료됨과 동시에 문자가 왔어요. [sin-cheong-i wan-nyo-doem-gwa dong-si-e mun-ja-ga wa-sseo-yo]
J. Choose the best pitfall reminder for -(으)ㅁ과 동시에.
Answer
✅ First make the formal noun with -(으)ㅁ, then add 과 동시에: 도착하다 → 도착함과 동시에, 받다 → 받음과 동시에. 🛡️
🛡️
Vocabulary Box
  • 도착하다 → to arrive
  • 받다 → to receive
  • 발표 → announcement / presentation
  • 읽다 → to read
  • 시작되다 → to begin / be started
  • 출발 → departure
  • 문 → door
  • 열리다 → to open / be opened
  • 사람 → person
  • 들어오다 → to come in
  • 공개 → release / public opening
  • 반응 → reaction
  • 신청 → application
  • 완료되다 → to be completed
  • 문자 → text message
  • 동시에 → at the same time
Tip 💡 Final boss rule: verb/adjective stem needs -(으)ㅁ과 동시에; noun event needs 과/와 동시에.
 
🎉 Practice complete. You can now write polished same-time sentences like 시작됨과 동시에, 도착함과 동시에, 읽음과 동시에, and 발표와 동시에. Timing grammar unlocked — very punctual of you. ⏱️✨