매튜의 한국어 연습 블로그

When you guess something and you're really sure about it, you use ~테니까. It conveys a slightly different feeling than 인니까 as they both explain the reason behind something but 테니까 is more like 75-80% sure while 인니까 is closer to 100% sure.

Comparison example:

비가 올테니까 우산을 가지고 가요
Since it's probably going to rain, take an umbrella with you.

비가 온니까 우산을 가져가요
Since it will definitely rain, take an umbrella with you.


Normal examples:

주말에는 명동이 붐빌테니까 다음 주 화요일에 쇼핑 할래요?
Since Myeongdong is probably be crowded on the weekend, do you want to go shopping next Tuesday?

걸어서 가면 시간이 많이 걸릴테니까 지하철을 타고 갈까요?
Since it's probably going to take a long time on foot, should we take the subway?

퇴근하는 대로 우리 외이프가 오면 피곤할 테니까 제가 집에서 저녁 식사를 차릴게요.
Because right after she gets off work my wife will probably be tired, I'll cook dinner home for her.

오늘 추울테니까 두꺼운 옷을 입으세요.
Since it'll likely be cold today, please wear thick clothes.

내일 도울테니까 반바지를 좀 사주세요.
Since tomorrow will probably be hot, can you buy me some shorts?

일본에 한동안 살아서 일본어 수업 들으면 쉬울테니까 걱정하지마요
Since you lived in Japan for a long time, if you take a Japanese class it'll probably be easy so don't worry.

자막이 없는 한국 영화를 보면 어려울테니까 미국 영화 볼래요?
Since watching a Korean movie without subtitles will probably be difficult, do you want to watch an American movie?


On a side note, there's a Kpop song that has this grammar point in the hook (or was it the bridge?) but I can't find it. The song sounded like 다라 from 2NE1 but I don't think it was one of her singles. Anyways, if you know it, leave a comment.
UPDATE: found it. It was 2NE1 not just Dara and it was "In da club". The bridge has the following lyrics:

니가 다짐했던 약속 다 가져가줄래
사소한 습관까지 작은 기억까지
모두 태울테니까
내 안에 살아있는 널 잠재울꺼야
니가 여태알던 내 모습은 이제 없는거야