을 테니까 vs 을 텐데 Lesson | I assume, I think that..

안녕하세요! Koreanstudyjunkie입니당^^

-(으)ㄹ테니까 = will/suppose.. (because); I think that, I assume... so

Usage: It’s used for making an assumption about a situation or about the future. You can think of it as “I’m pretty sure that…” or “I assume…” in English. You can use this assumption when you’re about 80% sure that what you are saying will happen or be true.

You can use this in the present and past tense. It can also be used to express a strong intention or plan in the first sentence and in the second sentence you’ll provide a suggestion or advice to the listener.

-(으)ㄹ 테니까 is often shortened to -(으)ㄹ 테니 without meaning change.

Form:

Present Tense:

consonant verb stem + 을 테니까/을 텐데

vowel verb stem + ㄹ테니까/ㄹ 텐데

Past Tense:

았/었을 테니까/ 았/었을 텐데

Example Sentences:

많이 추울 테니까 조심하세요. → It’s very cold, so be careful.

(This is an assumption.(“ I assume it will be very cold…”)

김밥 맛이 비슷할 테니까 그 식당까지 안 가도 돼. → (I assume that/I’m pretty sure that)

the Kimbap flavor will be similar, so you don’t have to go to that restaurant.

내일은 공부해야 할테니까 오늘 만날까요? → (I assume) I’ll have to study tomorrow, so shall we meet today?

퇴근 시간이라 길이 막힐 테니까 지하철을 타! → It’s rush hour, so I’m pretty sure there will be traffic, let’s take a taxi!

지수는 지금쯤 집에 도착했을 테니까 전화해 보세요. → Ji-Soo must have arrived home by now, so call her.

오늘 제가 밥을 살 테니 리사 시는 다음에 사세요. → I'll buy meal today, so Lisa, please do it next time.

제가 청소를 할 테니 후안 씨는 빨래를 하세요. → I'll clean up, so Huan, please do the laundry.

이 영화는 무서울테니 다른 영화를 보는 거 어때요? → This movie will be scary, so why don't we watch another movie?

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(으)ㄹ 텐데 = and, but, so..

Usage: This grammar ends withe ㄴ데 instead of 니까 so rather than meaning “because”, It means it’s more like “but”. This grammar shows contrast between 2 sentences, just like 는데.

In the first sentence you will acknowledge something (your assumption about the future) and in the second sentence you will have a sentence that contrasts it (mentions something opposite or different to the first sentence).

The same conjugation as ㄹ테니까.

Form:

Present Tense:

consonant verb stem + 을 테니까/을 텐데

vowel verb stem + ㄹ테니까/ㄹ 텐데

Past Tense:

았/었을 테니까/ 았/었을 텐데

Example Sentences:

내일은 공부해야 할텐데 오늘 만날까요? → I assume that I’ll have to study tomorrow, shall we meet today?

할 일이 많을 텐데 벌써 퇴근하려고? → You must have a lot of work to do, but you're leaving work already?

지금까지 아무것도 못 먹어서 배가 많이 고플 텐데 많이 먹어. → Because you haven’t eaten anything up until now, I assume you must be very hungry, so eat a lot.

내가 야근을 해서 늦을 텐데 너희들끼리 먼저 저녁을 먹는 게 어때? → (I’m pretty sure that) I'll be late because I’m working overtime, so why don't you guys have dinner first?

짐이 많아서 무거울 텐데 제가 좀 들어 줄까요? → It must be heavy due to a lot of luggage, do you want me to hold it for you?

기말시험에서 높은 점수를 받았을 텐데 왜 B를 줬어요? → I thought / I assumed that I got a good score on the final test. So why did you give me a B?

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That's all for this lesson! I did use GO! Billy’s lesson on ㄹ테니까/ㄹ텐데 as a reference to help me explain it, so if you need extra explanations I highly recommend watching his lesson on YouTube as well. There were more details that I didn’t cover in this post.