할 테니까 grammar - hal tenikka grammar

A/V-(으)ㄹ 테니까 grammar = suppose/will...(because) ~give reason for suggestion or advice

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

Tense:

Adjective/ Verb + -(으)ㄹ 테니까 (Present/future tense)

가다 --> 갈 테니까

먹다 --> 먹을 테니까

넓다 --> 넓을 테니까

맛있다 --> 맛있을 테니까

Adjective/ Verb + -았/었을 테니까 (Past tense)

가다 --> 갔을 테니까

먹다 --> 먹었을 테니까

넓다 --> 넓었을 테니까

맛있다 --> 맛있었을 테니까

Noun + 일 테니까 (Present/future tense)

아이 --> 아이일 테니까

학생 --> 학샐일 테니까

Noun + 였을/이었을 테니까 (Past tense)

아이 --> 아이였을 테니까

학생 --> 학샐이었을 테니까

Specific usage:

1. Can use at the end of a sentence -(으)ㄹ 테니까요 to express speaker’s assumption.

일찍 출발하세요. 금요일이라 길이 막힐 테니까요. 

Leave early. It's Friday, so there's going to be traffic jam.

2. Expressions such as 고맙다 and 미안하다 can't be used after -(으)ㄹ 테니까. A/V-(으)ㄹ 텐데 is used instead: 

바쁘실 텐데 참석해 주셔서 감사합니다.

You must be busy, but thank you for attending.

You must be tired, but I'm sorry for telling you to leave early.

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. 오늘은 많이 추울 테니까 따뜻하게 입어세요.

It’s going to be very cold today, so please dress warmly.

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

Perhaps, do you know Nami phone number?
- Since Anna knows 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.
- Then, it is better to prepare a lot of foods. Because of 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 suppose to leave now, so wait just a little bit more.

10. 학생일 테니까 깍까 주세요.

I'm a student, so please give me a discount.

Differences between A/V-(으)ㄹ 텐데 and A/V-(으)ㄹ 테니까 grammar

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)

배가 고플 텐데 어서 드세요. 

You must be hungry, so please have something to eat.

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)

배가 고플 테니까 어서 드세요.

(Because) You must be hungry, please have something to eat.

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).