Korean tense marking is relatively simple because compound sentences are generally structured in the order in which events occur or are recognized. In other words, Korean tends to follow the natural sequence of perception—the order in which events unfold as the speaker perceives or becomes aware of them.
Since the verb at the end of the sentence indicates the tense, this single marking is usually sufficient to convey the timing of the entire sequence. However, in some cases, preceding clauses must also mark the tense depending on sentence structure.
Beyond indicating tense, Korean also uses various connective endings to link clauses while maintaining this natural flow. However, these endings do more than simply link clauses—they also convey distinct nuances.
This chapter will explore how clauses are connected to form compound sentences and convey meaning in Korean by examining four basic connective endings: ‘-고,’ ‘-아서/-어서,’ ‘-(으)니(까),’ and ‘-ㄴ데/-은데/-는데.’
- 저는 한국어를 배우고, 민수는 일본어를 배워요. – I learn Korean, and Minsu learns Japanese.
- 오늘 저는 집에서 쉬었고, 미나는 학교에 갔어요. – I rested at home, and Mina went to school.
Firstly, the connective ending ‘-고’ links clauses in a coordinate structure. Since each clause conveys a distinct event or state, the subjects do not have to match. As a result, it is natural to mark tense separately in each clause.
- 손 씻고 식사합시다. – Let’s wash ours hands before eating.
- 엄마, 나 숙제하고 게임했어. – Mom, I played a video game after finishing my homework.
- 아직 집에 안 가고 여기서 뭐 해요? – What are you still doing here? I thought you went home.
- 너무 열심히 하지 말고 쉬세요. – Go easy on yourself and take some rest.
However, ‘-고’ also links clauses in a subordinate structure, indicating a chronological sequence of events. In this case, the subject of the linked clauses must match, and the subject is omitted in all but the first clause.
The direct translation of “손 씻고 식사합시다” and “엄마, 나 숙제하고 게임했어” would be “Let’s wash our hands and then eat” and “Mom, I finished my homework and then played a video game.”
On the other hand, Korean tends to place a supplementary clause before the main clause as seen in “아직 집에 안 가고 여기서 뭐 해요?” and “너무 열심히 하지 말고 쉬세요.” The direct translations would be “Instead of going home, why are you here ?” and “Don’t try too hard. Have a break” though the translations may vary depending on context.
- 여기까지 택시 타고 왔어요. – I came here by taxi.
- 오늘 추워요. 옷 많이 입고 오세요. – It’s cold today. Make sure you dress in layers.
- 우리는 앉아서 이야기했어요. – We sat down and talked.
- 이 셔츠는 꼭 뒤집어서 말리세요. – Please make sure you dry this shirt inside out.
At first glance, “-고” and “-아서/-어서” may seem interchangeable, as both indicate a sequence of actions or events. However, there is a key difference in nuance.
“-고” places greater emphasis on the process rather than the final state. In other words, it confirms that an action was completed at some point but does not necessarily imply that the result was maintained afterward.
For example, “여기까지 택시 타고 왔어요” confirms that the person took a taxi at some point, but it does not confirm whether they actually arrived by taxi or switched to another mode of transportation along the way. Similarly, “옷 많이 입고 오세요” instructs the listener to dress in layers before coming, but it does not necessarily mean that they kept those layers on upon arrival.
By contrast, “-아서/-어서” establishes a background condition, state, or event in which the main clause occurs. Thus, “앉아서 이야기했어요” confirms that the conversation happened while remaining seated, and “뒤집어서 말리세요” instructs the listener to dry the shirt while keeping it inside out.
- 시간이 부족해서 숙제를 못했어요. – I couldn’t finish my homework because I didn’t have enough time.
- 시간이 부족하니(까) 숙제를 못했어요. – Because I didn’t have enough time, I couldn’t finish my homework.
Since “-아서/-어서” functions to indicate a sequence of actions or events, it can also express the reason or cause of the main clause—which typically follows by a subordinate clause in Korean. Thus, the subordinate clause “시간이 부족해서” is interpreted as the reason: “because I didn’t have enough time.”
While “-아서/-어서” presents a reason or cause in a neutral and natural manner, “-(으)니(까)” conveys a stronger, more assertive reason. This is why “-(으)니(까)” is often used in imperative statements and direct requests, whereas “-아서/-어서” is more commonly found in explanations of cause-and-effect relationships.
- 비 오니까 막걸리 한잔하자. (O)
- 비 와서 막걸리 한잔하자. (X)
- 지금 기분 안 좋으니까 나한테 말 걸지 마. (O)
- 지금 기분 안 좋아서 나한테 말 걸지 마. (X)
As demonstrated, “-(으)니까” conveys a stronger and more direct reason, making it more suitable for requests and imperative statements. In contrast, “-아서/-어서” is generally restricted in such contexts, as it expresses a natural cause-and-effect relationship rather than a strong reason.
Fundamentally, the primary function of “-(으)니” is to introduce background information or a premise for the next statement. This allows “-(으)니” marked clauses to be interpreted in various ways depending on the context.
- 내가 무대로 올라가니(까) 사람들이 뜨거운 박수를 쳤다. – I walked up to the stage and people applauded enthusiastically.
- 내가 무대로 올라갔다. 사람들이 뜨거운 박수를 쳤다. I walked up to the state. People applauded enthusiastically.
- 직접 해 보니(까) 재밌었어요! – I tried it myself, and it was fun!
- 직접 했어요. 재밌었어요! – I tried it myself. It was fun!
One of the commonly used functions of “-(으)니(까)” is ‘discovery.’ The subordinate clause “내가 무대로 올라가니(까)” provides the background for the main clause, “사람들이 뜨거운 박수를 쳤다.” Therefore, the translation of the subordinate clause can be:
- “When I walked up to the stage,”
- “I walked up to the stage, and I found that,” or
- “Coming up to the stage.”
Similarly, “직접 해 보니(까)” can be translated as:
- “Trying it myself,”
- “After I’ve tried it,” or
- “I tried it myself, and realized that.”
However, in Korean, it is more natural to link these clauses rather than separate them.
- 옛날 옛적에 한 용감한 청년이 있었으니, 그의 이름은 홍길동이었다.
- 옛날 옛적에 한 용감한 청년이 있었는데, 그의 이름은 홍길동이었다.
Meanwhile, “-(으)니(까)” shares overlapping functions with “-ㄴ데/-은데/-는데” since “-ㄴ데/-은데/-는데” originated from the grammaticalization of the dependent noun “데,” which denotes a place, a case or a situation. Given their origins, it is crucial to mark the tense or aspect in subordinate clauses.
The translation of both “-으니” and “-는데” marked sentences in above examples is alike: ”Once upon a time, there was a brave young man, and his name was Hong Gil-dong.” However, there are subtle distinctions:
- “-으니” sounds formal and classical,
- “-는데” sounds more colloquial.
As a side note, the English translation of compound sentences with “-(으)니” and “-ㄴ데/-은데/-는데” generally mirrors the original Korean structure. Additionally, “-(으)니” in the sense of ‘discovery’ frequently appears with the verb ending “-더-,” which conveys an observer’s perspective based on what the speaker has seen or experienced, as shown in the following examples.
- 문을 열고 들어갔더니 거기엔 아무도 없었어요. – I opened the door and stepped inside, and I found that there was no one there.
- 문을 열고 들어갔는데 거기엔 아무도 없었어요. – I opened the door and stepped inside, and there was no one there.
- 삼촌이 결혼을 하더니 성격이 변했어. – After my uncle got married, his personality changed.
- 삼촌이 결혼을 했는데 성격이 변했어. – My uncle got married, and his personality changed.
Building on the previous explanation, “-더니” introduces background information or a premise for the next clause from the speaker’s perspective as an observer. Thus, “문을 열고 들어갔더니” can be translated as “I opened the door and stepped inside, and I found that…” Unlike “-는데,” which present presents two connected facts, “-더니” implies that the second clause resulted from or was observed after the first event.
Similar yet distinct, “-ㄴ데/-은데/-는데” marked clauses provide a setting, context or situation that enhances and clarifies the meaning of the following clause. In Korean, linking two statements with “-ㄴ데/-은데/-는데” sounds more natural and fluid than separating them. As a result, these constructions allow for a variety of interpretations or translations, as shown below.
- 이거 너무 매운데 괜찮아요? – This is super spicy. Are you good with spicy food?
- 여기 너무 맛있는데 다음에 다시 오자! – This place is so good. Let’s come back next time!
- 지금 밥 먹으려고 하는데 같이 먹을래? – I was just about to eat. Want to eat together?
- 제가 생각해 봤는데요, 오해가 좀 있었어요. – I thought about it, and I realized there was a misunderstanding.
- 똑같이 독감에 걸렸는데, 나는 아파서 죽겠는데 너는 너무 멀쩡하네! – We both have the flu, but I feel like I’m dying while you seem totally fine!
- 자는데 갑자기 전화가 와서 잠이 다 깨 버렸어. – I was asleep, but a sudden phone call woke me up completely.