Korean Makes You Choose a "Because"

English has one workhorse word for cause. You say because, you attach a clause to it, and the job is finished no matter what kind of cause you happened to be describing.

Korean does not give you that word at all. It gives you a shelf of endings instead, and the sentence cannot be built until you have taken one down and committed to it.

The choice is not decoration. It changes what you are allowed to say in the second half of the sentence, and it leaks information about how you feel about the cause.

Nineteen ways to say one English word

We can put a number on this, because the grammar reference behind our site is a file we can count.

The dataset holds 326 grammar points across 403 distinct senses. Nineteen of those senses are labelled as reason or cause by the source, and they belong to nineteen different grammar points.

That is roughly one in twenty of everything the reference covers, spent on a single English conjunction. Nothing else in the file is split that many ways.

Not all nineteen are live in speech. A few are literary, one is bureaucratic, and several overlap enough that a beginner can safely ignore them for a year or more. But the six or seven that remain are all common, all different, and none of them is freely interchangeable with the others.

아/어서, the neutral default

This is the first one learners meet and the one that covers the most ground. The dataset glosses it simply as reason or cause, with because of and therefore as its English equivalents.

그 옷은 작아서 못 입어요. — I can't wear these clothes because they're too small.

요즘에 바빠서 친구들을 못 만나요. — I can't meet my friends because I'm busy these days.

Both sentences state a fact and then state its consequence. Nobody is being asked to do anything in either one, and that detail turns out to matter enormously once you meet the next ending. The same form also has a second job in the dataset, listed as a sequence of events rather than a cause at all.

내일 친구를 만나서 영화를 볼 거예요. — I'm going to meet my friend tomorrow in order to watch a movie.

Nothing there is causal. The meeting simply has to happen before the film, and the ending is doing pure sequencing with no explanation attached to it anywhere.

You separate the two readings by asking whether the first clause explains the second or merely precedes it in time. Learners who never notice the split spend a long time confused by sentences that look identical and are not. The full entry lives at 아/어서.

(으)니까, the reason you can act on

The dataset labels this one reason or cause as well, with the same English gloss. The example it chooses is where the difference hides.

이번 주는 바쁘니까 다음 주에 합시다. — I'm busy this week, so let's do that next week.

That second clause is a suggestion, not a statement, and the distinction is doing real work. Korean lets 니까 carry a suggestion or a command behind it, and 아/어서 does not allow either one.

This is the single most useful thing to know about the pair, and it is a test you can run in a second. If the sentence ends in let's, please, or go ahead, the reason in front of it needs 니까 rather than 아/어서.

시간이 없으니 빨리 이동합시다. — Since we don't have time, let's move quickly.

That last one is the shorter (으/이)니, which the dataset files separately and glosses the same way. It behaves like 니까 with the tail cut off.

There is a second use of 니까 that has nothing to do with reason, and the file lists it as discovery.

아침에 회사에 가니까 아무도 없었어요. — When I went to the office in the morning, no one was there.

Going to the office did not cause the emptiness. The ending is marking the moment a fact was found, and English reaches for when rather than because. See (으)니까 for both senses side by side.

때문에, when the cause is a thing

The two endings above attach to verbs. This one attaches to a noun, which makes it the natural choice when the cause is an object or a condition rather than an event.

눈 때문에 길이 미끄러워요. — The road is slippery because of the snow.

감기 때문에 병원에 갔어요. — I went to the hospital because of the cold.

Snow and a cold are things rather than actions, and neither sentence needs a verb to name its cause. English does the same trick when it reaches for because of instead of plain because.

Verbs are not locked out of the pattern. The dataset notes that a verb can be nominalised with 기 first and then take the same particle without any further change.

날씨가 좋기 때문에 산에 갔어요. — I went to the mountain because the weather was good.

That detour through 기 is the tell. Korean is not bending the particle to fit a verb; it is turning the verb into a noun so the particle can keep doing what it already does. The entry is at 때문에.

(이)라서, the noun-shaped 아/어서

The reference describes this one bluntly as the 아/어서 equivalent for nouns, reachable only through the copula, which is why it never lands on a verb.

어머니 생신이라서 고향에 가야 돼요. — I have to go to my hometown because it's my mother's birthday.

제가 임산부라서 그러는데 이 자리에 앉아도 될까요? — I'm pregnant, so can I sit here?

Both causes are identities rather than events. A birthday and a pregnancy are states of affairs, and Korean marks them with the copula before the reason ending arrives.

The second sentence is worth keeping. It is a complete, polite way to ask a stranger for something, and the reason comes first because that is where Korean puts reasons. It is filed under (이)라서.

느라(고), the cause that used you up

Here is where English genuinely runs out of vocabulary. The dataset defines this ending as the preceding action being the purpose or cause of what follows, glossed as due to.

샤워를 하느라고 전화를 못 받았어요. — I couldn't answer the phone because I was taking a shower.

옷을 사느라고 돈을 다 썼어요. — I spent all my money buying clothes.

Look closely at what the two causes share. Each one consumed a resource that the second clause then turned out to lack: the shower took the time, and the shopping took the money.

That is the entire meaning of the ending, and English has no way to say it in a single word. A subtitle writes because and the resource-drain reading evaporates without leaving a trace behind.

Notice also that both results are negative ones. You did not answer the phone, you have nothing left to spend, and that flavour is baked into the form itself. The entry is 느라(고).

는 바람에, the cause nobody wanted

The file does not label this one reason or cause. It calls it an unintended consequence, and that is exactly the point of keeping it separate.

비가 오는 바람에 소풍을 취소했어요. — Because of the rain, we canceled the picnic.

전기가 나가는 바람에 TV를 못 봤어요. — I couldn't watch TV because the power went out.

Nobody wanted either outcome, and nobody in either sentence has to say so. The ending carries the disappointment entirely on its own, so the speaker never needs to add a word of complaint anywhere else in the line.

Swapping in a neutral 아/어서 here would still be grammatical, and it would quietly delete the speaker's attitude. That is the sort of loss you cannot detect in a translation, because the translation was never carrying it in the first place. Read the entry at 는 바람에.

길래 and 기에, one reason on two channels

These two are the clearest case in the whole dataset of a single meaning split purely by medium. Both are glossed as the reason or cause for the speaker's own action.

날씨가 따뜻하길래 산책을 했어요. — Since the weather was warm, I went for a walk.

날씨가 따뜻하기에 산책을 했다. — Since the weather was warm, I went for a walk.

The English is identical because the difference is not in the meaning. The reference marks 기에 as the written form and 길래 as its conversational counterpart, and notes that 길래 is common in speech.

Both examples share a restriction that is easy to miss. The second clause describes what the speaker did, so these endings do not work when somebody else is the one reacting.

사람들이 너무 많길래 다른 곳에 갔어요. — Because there were too many people, I went to a different place.

The crowd is the reason and the speaker is the one who moved. Entries: 길래 and 기에.

(으)므로, the cause that wears a suit

Some of these endings are sorted by attitude and some by register. This one is sorted almost entirely by where you are standing when you say it.

이 프로젝트는 중요하므로 모두가 참여해야 합니다. — Since this project is important, everyone must participate.

시간이 부족하므로 회의를 빨리 시작하겠습니다. — Since time is limited, we will start the meeting promptly.

The reference says plainly that it belongs to writing and to formal situations such as speeches and presentations. It also notes that 니까, 때문에 and 아/어서 can all replace it.

That last note is the useful half. The meaning is fully covered by endings you already have, so nothing is lost by leaving this one on the reading-only pile. It is at (으)므로.

The same institutional register produces a noun-side partner for it, which shows up in announcements and news copy constantly.

비로 인해 경기가 취소되었습니다. — The game was canceled due to rain.

That is (으)로 인하다, and it is the difference between because of rain and due to rain made grammatical rather than stylistic.

거든(요), the reason that arrives late

Every ending so far puts the reason in front of the result. This one does the opposite, and that is the whole reason it exists.

오늘은 공부해야 해요. 내일 중간시험을 보거든요. — I have to study today. Because I have a midterm exam tomorrow.

The claim is made first and then justified, in a separate sentence, after the listener has had a moment to wonder why. The dataset glosses it as reasoning the speaker has thought of.

English does this with intonation and a pause rather than with grammar. Korean gives the move its own ending, and a subtitle collapses the two sentences into one with because in the middle.

There is a second sense on the same form, listed as conditional, which is worth knowing so it does not ambush you.

비가 그치거든 축구를 할까요? — Shall we play soccer when the rain stops?

No reason is being given there at all. The full entry is 거든(요).

The ones you will only ever read

Three of the nineteen are effectively out of service for a speaking learner, and the dataset's own example sentences make that obvious.

봄이 되었거늘 날씨가 아직도 춥다. — Even though it's spring, the weather is still cold.

네가 진심으로 사과하나니 내가 용서하겠다. — Since you're sincerely apologizing, I will forgive you.

이미 밥을 먹은지라 더 이상 먹을 수가 없다. — I already ate, so I can't eat any more.

The reference describes the middle one as having a serious or solemn tone, and the first as often implying contrast or a rhetorical question. Neither belongs in a conversation you are likely to have.

They earn their place on the shelf anyway. You will meet them in subtitled historical drama and in written narration, where recognising the shape is enough. The entries are 거늘, 나니 and 는지라.

One more is worth a mention because it hedges rather than states, which no English conjunction manages on its own.

음식을 급하게 먹어서인지 소화가 잘 안 돼요. — Perhaps because I ate quickly, I'm having trouble digesting.

That is 아/어서인지, and the uncertainty sits in the ending rather than in an added adverb.

What a subtitle does to all of this

Every example on this page translates into English with the same three or four words. That is not a failure of the translators; it is the shape of the target language.

An English subtitle has exactly one slot for cause, and nineteen Korean forms have to queue up to use it. The line stays perfectly accurate, and none of the distinctions survive the trip across.

So a learner reading subtitles ends up with the plot and none of the grammar. You hear 느라고 and read because, and nothing on the screen tells you that a resource was just consumed by the first clause.

This is the specific gap our extension exists to close. It marks the grammar under the Korean subtitle line while the Korean is still on screen, which is the only moment the distinction is visible at all.

You can also work the other direction and browse the forms first, since all nineteen have their own pages in our Korean grammar reference.

Reading a reason in one pass

You do not need to hold nineteen forms in your head. You need four questions, asked in order, and they will place almost anything you hear.

1. Is the cause a noun or a verb? A bare noun in front takes 때문에 or 라서. A verb takes one of the endings.
2. What kind of clause follows? A suggestion or a command means 니까. A plain statement allows 아/어서.
3. Did the cause cost something? Time or money consumed points at 느라고. An unwanted outcome points at 는 바람에.
4. Where are you? A speech or a document takes 므로. A conversation takes 길래 rather than 기에.

Run those four and you will land on the right form far more often than chance. The remaining cases are literary, and for those recognition is genuinely enough.

The deeper habit is smaller than any of this. When you hear a reason in Korean, notice that a choice was made, because a speaker who picked 는 바람에 over 아/어서 told you something they never said.

FAQ

How do you say "because" in Korean?

There is no single word, so the answer depends on the sentence. For a verb cause with a plain result, use 아/어서. For a verb cause with a suggestion or command after it, use 니까. For a noun cause, use 때문에. Those three will cover the large majority of what you need to say.

What is the difference between 아/어서 and 니까?

The reliable difference is what each one allows after it. 니까 can be followed by a suggestion or a command, and 아/어서 cannot, which is why the dataset's own example for 니까 ends in a proposal to do something next week. Both are glossed as reason or cause, so the meaning is not where the split lives.

When should I use 때문에 instead of 아/어서?

Use 때문에 when the cause is a noun, such as snow, a cold or traffic. A verb can still get there by being nominalised with 기 first, which produces the 기 때문에 pattern. If the cause is naturally an action, 아/어서 is shorter and more ordinary.

What does 느라고 actually mean?

It marks a cause that consumed something the second clause then lacked, usually time or money, and the result is usually negative. Taking a shower is why the phone went unanswered; buying clothes is why the money is gone. English has no one-word equivalent, which is exactly why subtitles flatten it into a plain because.

Is 는 바람에 the same as 때문에?

They overlap in translation and differ in attitude. 는 바람에 carries an unintended and usually unwelcome result, so a cancelled picnic or a missed programme fits it naturally. 때문에 is neutral and will not tell the listener how you feel about what happened.

How many ways of saying "because" do I actually need?

Four will carry you a long way: 아/어서, 니까, 때문에 and 느라고. Add 는 바람에 and 길래 once those are automatic, and treat 므로, 거늘, 나니 and 는지라 as reading vocabulary. The remaining forms are variations you will absorb from exposure rather than study.

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Every ending, gloss and example sentence on this page was read from the kimchi-grammar dataset that powers our grammar pages, published under CC BY 4.0. The counts quoted here were computed over that same file: 326 grammar points, 403 senses, 18 of them labelled reason or cause. No line was taken from a subtitle track or a broadcast.