L2G04 A/V/N-(으)ㄹ 테니까 grammar = because.., will/would/must be… ~give reason for suggestion.

L2G04 A/V/N-(으)ㄹ 테니까 grammar = because…., will/would/ should/ must be… ~give reason for suggestion.

Usage:
- Equal to -(으)ㄹ 터이다 (future situation or intention) + -(으)니까 (gives reason)
- Express  the speaker's strong supposition (1st clause) and becomes a reason or condition for suggestion or advice (2nd clause) = suppose, will
- Can use at the end of a sentence -(으)ㄹ 테니까요 to express speaker’s assumption.
- Not use if 고맙다, or 미안하다 is followed (use -(으)ㄹ 텐데 instead: e.g. 바쁘실 텐데 참석해 주셔서 감사합니다.)

Tense:

Adjective/ Verb:
- 과거 : 았/었을 테니까
- 현재 / 미래 : -(으)ㄹ 테니까

Noun:
- 과거 : 였을 테니까
- 현재 / 미래 : 일 테니까

Examples:

1. 비빔밥에는 고추장을 넣어야 맛있지요?
- 네, 하지만 고추장을 많이 넣으면 매울 테니까 조금만 넣으세요.

Bibimbap need pepper sauce to taste good, right?
- Yeah, but if you add much pepper sauce, it will be spicy, so just add a little.

2. 나미 씨가 면접을 잘 봤는지 모르겠어요.
- 잘 봤을 테니까 걱정하지 마세요.

I wonder if Nami did well on her interview.
- I am sure he did well, so don't worry.

3. 요즘 딸기 철이라 딸기가 싸고 맛있을 테니까 딸기를 사 가요.

Because it is strawberry season now, it should be cheap and taste good, so let's buy some strawberries.

4. 일찍 출발하세요. 월요일이라서 길이 막힐 테니까요.

Leave early. Since it is Monday, the road would be jammed.

5. 혹시 나미 씨 전화 번호 아세요?
- 안나 씨가 알 테니까 안나 씨한테 물어보세요.

Perhaps, do you know Nami phone number?
- Since Anna know that, please ask Anna.

6. 마리 씨가 자고 있을 테니까 이따가 전화합시다.

Since Mary is sleeping, let's call her after a while.

7. 주말에 파티를 하기로 했어요.
- 그럼, 음식을 많이 준비하는 게 좋겠어요.  주말이라서 사람들이 많이 올 테니까요.

I planned to make a party in the weekend.
- So, it is better to prepare a lot of foods. Since it is weekend, many people would come.

8. 이번 휴가에 어디로 갈까요?
- 바다에는 사람이 많을 테니까 산에 가는 게 어때요?

Where shall we go in this vacation?
- Since there are many people going to the sea, how about going to the mountain.

9. 지금 갈 테니까 조금 더 기다려 주세요
I’m going to leave now, so wait just a little bit more.

10. 학생일 테니까 깍까 주세요.

Since I am a student, please give me a discount.

Comparison -(으)ㄹ 텐데 vs -(으)ㄹ 테니까:

1. -(으)ㄹ 텐데 refers to the actual situation related to the assumption (not know about the situation perfectly since it is just considered at the moment)

E.g. 배가 고플 텐데 어서 드세요. --- You must be hungry, so please have something to eat.

E.g. 길이 막힐 텐데 지하철로 가자.--- The street would be jammed, so let's take the subway.

2. -(으)ㄹ 테니까 refers to the reason for assumption. (know about the situation with conviction since it was known well or frequently repeated by the speaker)

E.g. 배가 고플 테니까 어서 드세요. --- (Because) You must be hungry, please have something to eat.

E.g. 길이 막힐 테니까 지하철로 가자.--- (Since) The street would be jammed, so let's take the subway.

Note that: the grammars can be used interchangeably in some situations. However, the use of -(으)ㄹ 테니까 is more common and more natural in terms of giving an intention (suggestion or advice).