Overview
V+(으)니까 is a versatile connective ending used to express the reason or cause for the action or state described in the following clause. A key nuance of this ending is its use when the speaker discovers or realizes the reason, or when the reason leads to a command, suggestion, or request.
Usage
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Stating a Reason or Cause: The primary function of V+(으)니까 is to provide the reason or justification for the subsequent clause. It establishes a cause-and-effect relationship.
- Example: 날씨가 좋으니까 산책하러 갈까요? (Since the weather is good, shall we go for a walk?)
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Expressing Discovery or Realization: This ending is often used when the speaker has just become aware of or discovered the reason for something. The first clause describes the discovery, and the second clause describes the action taken as a result.
- Example: 문을 여니까 바람이 들어왔어요. (When I opened the door, the wind came in. - discovery of wind upon opening)
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With Commands, Suggestions, or Requests: Unlike some other reason endings, V+(으)니까 can be freely used with imperative (-으세요), propositive (-읍시다), and interrogative (-을까요) endings in the following clause. This is a crucial distinction.
- Example: 피곤하니까 좀 쉬세요. (Because you're tired, please rest a bit.)
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Sequential Relationship: It can sometimes imply a temporal sequence where the first action or state leads to the second, often with a discovered consequence.
- Example: 집에 오니까 아무도 없었어요. (When I came home, nobody was there. - discovery upon arrival)
Conjugation Rules
Attach V+(으)니까 to the stem of verbs and adjectives.
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If the verb/adjective stem ends in a vowel or ㄹ (final consonant), attach -니까.
- 가다 (to go) -> 가 + 니까 -> 가니까
- 오다 (to come) -> 오 + 니까 -> 오니까
- 만들다 (to make) -> 만들 + 니까 -> 만드니까
- 길다 (to be long) -> 길 + 니까 -> 기니까
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If the verb/adjective stem ends in a consonant (other than ㄹ), attach -으니까.
- 먹다 (to eat) -> 먹 + 으니까 -> 먹으니까
- 읽다 (to read) -> 읽 + 으니까 -> 읽으니까
- 작다 (to be small) -> 작 + 으니까 -> 작으니까
Irregular Verbs/Adjectives: The irregular rules apply before adding -(으)니까.
- ㄷ irregular: 듣다 (to listen) -> 들으니까
- ㅂ irregular: 춥다 (to be cold) -> 추우니까
- ㅅ irregular: 낫다 (to be better) -> 나으니까
- 르 irregular: 모르다 (to not know) -> 모르니까 (no change for 르 irregular before -니까)
Knowledge Plus
- Distinction from -아서/어서: While both express reason, V+(으)니까 and V+-아서/어서 have key differences:
- Commands/Suggestions: V+(으)니까 can be used with imperative and propositive endings (e.g., -으세요, -읍시다, -을까요), whereas -아서/어서 cannot.
- Tense: V+(으)니까 can attach to past tense (-았/었으니까) or future tense (-겠으니까) forms in the first clause. -아서/어서 cannot directly attach to past or future tense markers in the first clause.
- Discovery/Sequentiality: V+(으)니까 often implies a discovery or realization of the reason, or a sequential relationship where the first event leads to the second. -아서/어서 generally states a more direct, non-sequential cause-and-effect.
- Subject Agreement: The subjects of the two clauses connected by V+(으)니까 can be different, allowing for a wide range of expressions.
- Politeness: V+(으)니까 is a neutral connective ending and can be used in both formal and informal contexts.