-ㄴ/는/ㄹ 테니(까)

How It Works

Examples (5)

1. 제가 설거지를 할 테니까, 민준 씨는 방을 청소해 주세요.

   I'll do the dishes, so Minjun, please clean the room.

   Word by Word: I the dishes will do since, Minjun Mr. room please clean.

   This shows the 'speaker's intention' usage. The speaker states their action (doing the dishes) as the reason for requesting the listener to do another action (clean the room).

2. 밖에 비가 올 테니까 우산을 가져가세요.

   It will probably rain outside, so please take an umbrella.

   Word by Word: Outside rain will probably come since umbrella please take.

   This shows the 'speaker's supposition' usage. The speaker is guessing it will rain, and this guess is the reason for the command to take an umbrella.

3. 회의가 길어질 테니 미리 화장실에 다녀오세요.

   The meeting will probably get long, so please go to the restroom beforehand.

   Word by Word: The meeting will probably become long since in advance to the restroom please go and come back.

   Another example of supposition. The speaker anticipates a long meeting and gives advice based on that.

4. 지금 출발할 테니까 조금만 기다려 주세요.

   I'm leaving right now, so please wait just a little.

   Word by Word: Now leaving since a little only please wait.

   Even for an action happening right now, 테니까 takes -(으)ㄹ → 출발할 테니까. There is no -는 테니까 form.

5. 어제 밤을 새웠을 테니 피곤하겠네요. 어서 들어가서 쉬세요.

   You must be tired since you probably stayed up all night yesterday. Please go in and rest.

   Word by Word: Yesterday night probably stayed up since must be tired. Quickly go in and please rest.

   This uses the past tense '-았/었을 테니' to make a supposition about a past event (staying up all night) and gives a suggestion based on its current result (being tired).

Common Mistakes

• Using -ㄹ 테니까 for a simple, objective reason instead of -(으)니까 or -아/어서.

  Not Quite어제 많이 잤을 테니까 오늘 피곤하지 않아요.

  Better어제 많이 잤으니까 오늘 피곤하지 않아요.

  '-ㄹ 테니까' implies the speaker's guess or intention as a reason for a suggestion or command to someone else. For stating a simple, factual cause and effect about your own state, -(으)니까 or -아/어서 is more natural.

• Using a simple past-tense statement in the second clause.

  Not Quite날씨가 추울 테니까 저는 두꺼운 옷을 입었어요.

  Better날씨가 추울 테니까 저는 두꺼운 옷을 입을 거예요.

  The clause following -ㄹ 테니까 should not be a simple past-tense statement. It should be a command, suggestion, or a statement of future intention (like -ㄹ 거예요). The correct example means 'Since it will probably be cold, I'm going to wear thick clothes.'

Learn This First

To express future assumptions with reasons, you need modifier forms and causal patterns.

• -ㄴ/는/ㄹModifier Endings

  This uses various modifier forms for different tenses.

• -(으)니까So, Because

  This builds on the causal pattern -니까.

Related Patterns

• -ㄴ/는/ㄹ 텐데I Expect, It's Likely to

  Both patterns express a supposition. However, -ㄹ 텐데 is used to provide background information, often with a sense of contrast or unfulfilled expectation ('It's probably X, but...'). -ㄴ/는/ㄹ 테니(까) uses the supposition as a direct reason for a following command or suggestion ('Since it's probably X, you should...').

• -(으)ㄹ게Will Do

  Both can express the speaker's intention. -ㄹ게 is a simple promise or statement of intent made to the listener ('I will do...'). -ㄴ/는/ㄹ 테니(까) uses that same intention as a reason for the listener to do something else ('Since I will do X, you do Y').

• -아/어서Because of, Therefore

  Like -니까, -아/어서 also indicates a reason. However, it shows a more general, logical cause-and-effect relationship and, crucially, cannot be followed by commands or suggestions. -ㄴ/는/ㄹ 테니(까) is specifically designed to be followed by them.

Words in This Pattern