Complementizers are used to create noun clauses or phrases that serve specific functions in a sentence. It can effectively distinguish between the main clause and the subordinate clause.
Types of Complementizers
1. Verb Stem + ~는 / (으)ㄴ / (으)ㄹ 것, ~다는 / 냐는 / 라는 / 자는 것
2. Verb Stem + ~는 / (으)ㄴ / (으)ㄹ / 았는 / 었는 지
3. Verb Stem + ~는 / (으)ㄴ / (으)ㄹ 줄
4. Verb Stem + ~는 / (으)ㄴ / (으)ㄹ 바
Verb Stem + ~는 / (으)ㄴ / (으)ㄹ 것
The complementizer “~것” has no specific meaning other than the generic meaning such as “the thing that,” “the fact that,” and so on.
| Verb Type | Tense | Complementizer | Example |
| Action Verb | Present | ~는 것 (after a consonant or a vowel) | 저는 먹는 것을 좋아해요. (I like eating) |
| Past | ~은 것 (after a consonant) | 내가 만든 것은 복잡했다. (The thing that I made was complicated) | |
| ~ㄴ 것 (after a vowel) | 그가 쓴 것을 이해할 수 없었다. (I could not understand what he wrote) | ||
| Future | ~을 것 (after a consonant) | 선생님은 내일 시험이 있을 것이라고 말씀하셨다. (The teacher said that it will be a test tomorrow) | |
| ~ㄹ 것 (after a vowel) | 친구는 우리 집에 놀러 올 것이 분명하다. (It is obvious that my friend will come over to my house) | ||
| Stative Verb | All | ~은 것 (after a consonant) | 키가 작은 것이 문제다. (The problem is that I am short) |
| ~ㄴ 것 (after a vowel) | 수지는 음식이 짠 것을 불평했다. (Suju complained that the food is salty) |
Verb Stem + ~다는 / 냐는 / 라는 / 자는 것
The complementizer “~것” can be combined with different forms to indicate that a preceding subordinate clause is actually a citation from something someone else.
| Type | Complementizer | Example |
| Statement | ~다는 것 | 그는 내일 회의가 있다는 것을 싫어했다. (He hated that there would be a meeting tomorrow) |
| Question | ~냐는 것 | 왜 말도 없이 집에 갔냐는 것을 물어봤다. (I asked why he/she left home without saying a word) |
| Imperative | ~라는 것 | 조용히 하라는 것 때문에 사람들과 싸웠다. (I fought with the people because I ordered them to be quiet) |
| Proposition | ~자는 것 | 이번 주말에 같이 여행 가자는 것을 거절했다. (I turned down the suggestion to go on a trip together this weekend) |
Verb Stem + ~는 / (으)ㄴ / (으)ㄹ / 았는 / 었는 지
The word “whether” in English is used to connect a main clause with a subordinate clause. It shows a boundary between these two parts of the sentence. However, “whether” can only be used with certain verbs, like “to suspect,” “to know,” “to question,” etc.
In Korean, the complementizer “~지” works like “whether.” It makes the whole sentence work like a noun, so it can act as the subject or the object in a sentence, just like a regular noun.
However, the complementizer “~지” is usually used with specific verbs:
1. 걱정하다 (to worry)
2. 의심하다 (to suspect)
3. 알다 (to know)
4. 묻다 (to question)
The complementizer “~지” does not carry any meaning itself. But it shows that there’s some uncertainty or doubt, like when someone is wondering or questioning something.
| Verb Type | Tense | Complementizer | Example |
| Action Verb | Present | ~는 지 (after a consonant or a vowel) | 내일 비가 오는 지(가) 궁금하다. (I wonder whether it will rain tomorrow) |
| Past | ~있는 지 (if the preceding syllable contains the vowel “오” or “아”) | 집에 잘 갔는 지(가) 궁금했다. (I wondered whether he/she went home well) | |
| ~었는 지 (Otherwise) | 저녁을 먹었는 지(를) 몰랐다. (I did not know whether you had dinner) | ||
| Future | ~을 지 (after a consonant) | 미팅이 있을 지(를) 모르겠다. (I don’t know whether there will be a meeting) | |
| ~ㄹ 지 (after a vowel) | 어떻게 할 지(를) 모르겠어요. (I don’t know what to do) | ||
| Stative Verb | All | ~은 지 (after a consonant) | 그 제품이 얼마나 좋은 지(가) 궁금해요. (I wonder how good the product is) |
| ~ㄴ 지 (after a vowel) | 이 곳이 얼마나 예쁜 지(를) 알겠어요. (I can know how pretty this place is) |
Verb Stem + ~는 / (으)ㄴ / (으)ㄹ 줄
The complementizer “~줄” is similar to the complementizer “~지” but is more limited in its use. It can only act as the object of a sentence, not as the subject.
*This “~줄” uses different suffixes regarding action verbs in the past tense.
Ex) ~을 줄 / ~ㄹ 줄 => ~은 줄 / ~ㄴ 줄
| Verb Type | Tense | Complementizer | Example |
| Action Verb | Present | ~는 줄 (after a consonant or a vowel) | 아무도 너가 숨어 있는 줄(을) 모른다. (No one knows that you are hiding) |
| 아무도 너가 숨어 있는 줄(이) 모른다. (X) (It cannot be used as the subject) | |||
| Past | ~은 줄 (after a consonant) | 그 책을 다 읽은 줄(을) 알았다. (I thought you had already finished reading the book) | |
| ~ㄴ 줄 (after a vowel) | 이미 집에 간 줄(을) 몰랐다. (I did not know that you already went home) | ||
| Future | ~을 줄 (after a consonant) | 내일 시험이 있을 줄(을) 몰랐습니다. (I did not know that there will be a test tomorrow) | |
| ~ㄹ 줄 (after a vowel) | 우리는 네가 쉽게 이길 줄 알았어. (We thought you would win easily) | ||
| Stative Verb | All | ~은 줄 (after a consonant) | 음식이 맛있을 줄 몰랐다. (I did not know the food would be delicious) |
| ~ㄴ 줄 (after a vowel) | 사람들은 너가 그녀를 좋아하는 줄(을) 안다. (People think that you like her) |
Verb Stem + ~는 / (으)ㄴ / (으)ㄹ 바
The complementizer “~바” has the same function. But it is much more restricted than the complementizer “~줄.” It is only used with a few action verbs in specific idiomatic expressions.
| Verb Type | Tense | Complementizer | Example |
| Action Verb | Present | ~는 바 (after a consonant or a vowel) | 아시는 바와 같이 오늘 방문하세요. (As you know, please visit today) |
| Past | ~은 바 (after a consonant) | 그 이야기를 전에 들은 바가 없습니다. (I have not heard of that story before) | |
| ~ㄴ 바 (after a vowel) | 내가 경험한 바로는 문제 없었다. (There was no issue from what I experienced) | ||
| Future | ~을 바 (after a consonant) | 그 음식을 먹을 바에야 굶는 게 낫다. (It would be better not to eat anything rather than eating that food) | |
| ~ㄹ 바 (after a vowel) | 그건 내가 알 바(가) 아니다. (It is nothing that I need to be concerned about) |