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Grammar / Level 2 / Lesson 39

(으)니까 and 기 때문에: three becauses

By Daniel Buckley · 12 minute read · TOPIK 2

Vocabulary

  1. 때문 - cause, reason
  2. 놓치다 - to miss (a bus, a chance)
  3. 왜냐하면 - the reason is, because
  4. 우산 - umbrella
  5. 가져가다 - to take (with you)
  6. 미끄럽다 - to be slippery
  7. 조심하다 - to be careful
  8. 일찍 - early
  9. 출근하다 - to go to work
  10. 문장 - sentence

You're late and you want your friend to hurry. 늦어서 빨리 가세요 looks fine and isn't, as lesson 23 warned. English gives no clue why, because it would use "so" for all of this.

Korean has three common ways to give a reason. They overlap in meaning, and the choice mostly depends on what you're doing with the reason: reporting it, using it to get someone to act, or setting it out formally.

(으)니까: since

(으)니까 goes on the stem and gives grounds for what comes next. Where 아/어서 reports that one thing led to another, (으)니까 feels more like "here's why I'm saying this". I read it as "since", and that may be why it can lead into a command: a command wants grounds, and this supplies them.

Making (으)니까

  • Stem ends in a vowel: add 니까.가다 → 가니까바쁘다 → 바쁘니까
  • Stem ends in a consonant: add 으니까.먹다 → 먹으니까없다 → 없으니까
  • Stem ends in ㄹ: the ㄹ drops, then add 니까.살다 → 사니까멀다 → 머니까
  • Past: add 으니까 to the 았/었 stem.먹었으니까갔으니까
  • Nouns: add 이니까, or 니까 after a vowel.일요일 → 일요일이니까친구 → 친구니까

Pick a verb

가다가가니까

  1. 비가 오니까 우산을 가져가세요.

    Rain comes, so please take umbrella.

  2. 시간이 없으니까 빨리 갑시다.

    Time doesn't exist, so (let's) go quickly.

  3. 오늘은 바쁘니까 내일 만날까요?

    Today (I) am busy, so shall (we) meet tomorrow?

  4. 날씨가 추우니까 안으로 들어가요.

    Weather is cold, so (let's) go inside.

  5. 늦었으니까 택시를 타세요.

    (It) is late, so please take taxi.

  6. 내일은 일요일이니까 같이 등산할까요?

    Tomorrow is Sunday, so shall (we) hike together?

Unlike 서, it takes tense. 았/었 goes in front, as in example 5, and so does the future: 제가 갈 거니까 걱정하지 마세요, I'll be going, so don't worry.

※ 그러니까 is the same ending on 그렇다, and it starts a sentence just as 그래서 does. In speech it also means "I mean" or "so what I'm saying is", and 그러니까요 is "exactly".

(으)니까: I did it and found

(으)니까 has a second job that has nothing to do with reasons. The first clause is something you did, and the second is what you found when you did it. English says "when" or "and found".

The sentence usually ends in the past, but the first clause takes no 았/었. That's your clue, along with the fact that the first event didn't cause the second.

  1. 집에 오니까 아무도 없었어요.

    (I) came home and found nobody was there.

  2. 아침에 일어나니까 열 시였어요.

    In the morning (I) got up and found (it) was ten o'clock.

  3. 창문을 여니까 눈이 오고 있었어요.

    (I) opened window and found snow was coming.

  4. 학교에 가니까 문이 닫혀 있었어요.

    (I) went to school and found door was closed.

(으)니: the short written form

Take 까 off and you have (으)니. It means the same as (으)니까, but it reads as more written: signs, notices and formal messages. In conversation, stick to (으)니까.

  1. 바닥이 미끄러우니 조심하세요.

    Floor is slippery, so please be careful.

  2. 날씨가 추우니 따뜻하게 입으세요.

    Weather is cold, so please dress warmly.

  3. 비가 오니 우산을 가져가세요.

    Rain comes, so please take umbrella.

때문에 and 기 때문에

때문 is a noun meaning cause, so 때문에 is "because of". It goes straight after a noun. To use it with a whole clause, turn the clause into a noun with 기, and 비가 오다 becomes 비가 오기 때문에.

Making 때문에

  • After a noun: 때문에.비 → 비 때문에시험 → 시험 때문에
  • After a verb or adjective: 기 때문에.오다 → 오기 때문에있다 → 있기 때문에
  • Past: add 기 때문에 to the 았/었 stem.먹었기 때문에갔기 때문에
  • "Because it is" a noun: 이기 때문에.학생 → 학생이기 때문에

  1. 비 때문에 못 갔어요.

    Because of rain, (I) couldn't go.

  2. 시험 때문에 바빠요.

    Because of exam, (I) am busy.

  3. 일 때문에 부산에 왔어요.

    Because of work, (I) came to Busan.

After a noun, 때문에 often points at something that went wrong, so 저 사람 때문에 can sound like blame. When the cause was a good thing, Koreans tend to say 덕분에, which comes in Level 3.

기 때문에 is the heaviest of the three. It puts weight on the reason and sounds like an explanation, so it's at home in writing, speeches and news. It usually doesn't lead into a command or suggestion, and in that way it behaves like 아/어서.

  1. 오늘은 회의가 있기 때문에 일찍 출근합니다.

    Because meeting exists today, (I) go to work early.

  2. 어제 잠을 못 잤기 때문에 오늘 피곤합니다.

    Because (I) couldn't sleep yesterday, (I) am tired today.

  3. 한국어는 동사가 문장 끝에 오기 때문에 끝까지 들어야 합니다.

    Because in Korean verb comes at end of sentence, (you) have to listen to the end.

  4. 저는 학생이기 때문에 돈이 많지 않습니다.

    Because I am student, (I) don't have much money.

End a sentence with 때문이에요 and you get "it's because". In a careful explanation, 왜냐하면 often starts that sentence.

  1. 늦었습니다. 버스를 놓쳤기 때문입니다.

    (I) am late. (It) is because (I) missed bus.

  2. 왜냐하면 일이 너무 많기 때문이에요.

    The reason is, (it) is because work is too much.

Choosing a because

In plain statements more than one often works: 바빠서 못 가요 and 바쁘니까 못 가요 are both fine. So don't look for one right answer every time. Start from the default in this box, and the other lines cover the places where the choice matters.

Which one to use

  • You're just saying why something happened: 아/어서 is the safe default.비가 와서 집에 있어요.
  • Sorry, thank you, nice to meet you: 아/어서.늦어서 죄송합니다.도와줘서 고마워요.
  • A command, request or suggestion comes next: (으)니까.시간이 없으니까 빨리 가세요.
  • Writing, a speech, a formal explanation: 기 때문에.비가 많이 왔기 때문에 길이 막혔습니다.
  • Because of a noun: 때문에.시험 때문에 바빠요.
  • Answering 왜: 아/어서요 is the plain reply.버스를 놓쳐서요.

Why do thanks and apologies take 아/어서? Here's how I'd explain it. With 아/어서 the feeling simply follows from what happened, while 늦었으니까 죄송합니다 sounds as if you're arguing for your apology.

This feel carries into answers. To 왜 늦었어요?, 버스를 놓쳐서요 is the plain reply. 버스를 놓쳤으니까요 is grammatical, but it can sound as if the reason should have been obvious, so I'd take care with it around people above you.

  1. ___ 죄송합니다.

    Sorry I'm late.

  2. 시간이 ___ 빨리 갑시다.

    We don't have time, so let's go quickly.

  3. 왜 늦었어요? 버스를 ___.

    Why are you late? I missed the bus. (Said to your boss.)

  4. ___ 못 갔어요.

    I couldn't go because of the rain.

  5. 저는 ___ 표가 더 싸요.

    Because I'm a student, my ticket is cheaper.

  6. 집에 ___ 아무도 없었어요.

    I got home and found nobody there.

Listen and type

1 / 3

Play it as often as you like.

In a conversation

A

오늘 왜 이렇게 피곤해 보여요?

Today why so tired look?

B

시험 때문에 어제 잠을 못 잤어요.

Exam because of yesterday sleep couldn't sleep.

A

일이 다 끝났으니까 집에 가서 쉬세요.

Work all finished, so go home and rest.

B

네, 걱정해 줘서 고마워요.

Yes, worried for me, so thankful.

A

내일은 회의가 없으니까 천천히 오세요.

Tomorrow meeting doesn't exist, so slowly please come.

Common mistakes

  1. 비가 와서 우산을 가져가세요.

    비가 오니까 우산을 가져가세요.

    The "so" of 아/어서 can't lead into a command. (으)니까 can.

  2. 도와줬으니까 고마워요.

    도와줘서 고마워요.

    Thanks and apologies take 아/어서. (으)니까 makes them sound like an argument.

  3. 시험이 때문에 바빠요.

    시험 때문에 바빠요.

    때문에 goes directly on a noun, with no 이/가 in between.

Check yourself

Quick check

1 / 6

비가 ___ 우산을 가져가세요. (오다, use (으)니까) It's raining, so take an umbrella.

A command comes next.

Summary

(으)니까 forms
DictionaryStem(으)니까
가다가가니까
먹다먹먹으니까
살다살사니까
듣다듣들으니까
춥다춥추우니까
하다하하니까
기 때문에 forms
DictionaryStem기 때문에
가다가가기 때문에
먹다먹먹기 때문에
살다살살기 때문에
듣다듣듣기 때문에
춥다춥춥기 때문에
하다하하기 때문에

The three becauses

  • 아/어서: the default. No past before it, and no command after its "so" meaning.
  • (으)니까: takes the past, and can lead into a command or suggestion. (으)니 is the written short form.
  • 기 때문에: formal and weighty. Takes the past, and usually no command after it. After a noun, just 때문에.

Now you can say

  1. 시간이 없으니까 빨리 갑시다.

    Time doesn't exist, so (let's) go quickly.

  2. 시험 때문에 바빠요.

    Because of exam, (I) am busy.

  3. 집에 오니까 아무도 없었어요.

    (I) came home and found nobody was there.

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