Let's learn about "-ㄴ 거야"

See : https://milkcocoahkorean.tumblr.com/post/181321582728/%E3%84%B4%EB%8A%94-%EA%B1%B0%EC%95%BC-grammar

ㄴ/는 거야 or the polite ㄴ/는 거예요 is a sentence ending that can be used in the present or past with both verbs and adjectives. It’s basically a more emotional way to talk instead of giving just basic information or straight facts.

And, it’s used mostly in these situations:

–> giving new (or surprising) information

–> responding to something (with emotion)

–> telling a story to someone (this is because you’re typically telling new or surprising information haha)

–> recounting or clarifying information

So, here are the basic conjugations.

Verbs:

No 받침 present tense 는 거야/는 거예요 / No 받침 past tense ㄴ 거야/ㄴ 거예요.

하는 거야 (하다/하고 있다) / 한 거야 (했다)

Yes 받침 present tense 는 거야/는 거예요/ Yes 받침 past tense 은 거야/은 거예요

먹는 거야 (먹다/먹고 있어) / 먹은 거야 (먹었다)

Adjectives:

No 받침 —> ㄴ 거야/ㄴ 거예요

슬픈 거야 (슬프다)

Yes 받침 —> 은 거야/은 거예요

좋은 거야 (좋다)

Adjectives don’t really get treated as having a past tense in many Korean grammatical structures because it’s often seen as an unchanging state.

Here are some examples:

그거 들었어? 소영이가 그 오빠랑 사귀는 거야! Did you hear that? Soyoung is dating that older guy!

This sounds more surprised like “I’m telling you something!” Instead of “그 오빠랑 사귀고 있어” which just conveys the information a little more dryly. So, if you don’t care, you might use 사귀고 있어. But if this is big news, 사귀는 거야 is more likely to be used. 

어제 남자친구가 갑자기 헤어지자고 한 거야. Yesterday, my boyfriend suddenly said we should break up! (let’s break up). 

이쪽으로 갈까? (Goes off in another direction.) 엥? 어디 가는 거야! 이리 와! Should we go in this direction? *goes off in another direction.* Eh? Where are you going??

*Like “Where on earth are you going” or “where exactly are you going?” or “where the hell are you going?”

It’s actually tough to use naturally. And, it will take a lot of listening to others use it and practice before you really master it! Because it is used all the time.

But, it’s not used for just conveying facts. Here is an example.

A: 뭐 해? What are you doing?

B: 공부하고 있어. I’m studying.

A: 금요일이잖아. 공부가 그렇게 좋아? It’s Friday. Do you like studying that much?

B: 내일 시험이 있어서 공부하는 거야. I’m studying because I have a test tomorrow.

Here you can’t replace 공부하고 있어 with 공부하는 거야. It would be unnatural because you’re only conveying a fact with no emotion or response or wish to tell this person something surprising. But the second instance has some emotion in it.

Or here.

A: 너 계란 있어? Do you have any eggs?

B: 없어요. No. (I don’t have any.)

A: 그럼 빵은 있어? Then, do you have bread?

B: 그것도 없어요. I don’t have any of that either.

A: 그럼 우유는 있어? Then, do you have any milk?

B: 아 그것도— ah that too–

A: 그것도 없는 거야? 너 굶어 죽고 싶은 거야?? You don’t have that either? Do you want to starve to death??

By the end of the conversation, A can easily express annoyance or surprise that B has no food in their house. 

Tip: You’ll see this written and pronounced often as 는 거에요 instead of 는 거예요 in formal speech. It’s probably because it’s a little easier to say. There are many Koreans who don’t know the correct spelling of this grammar point. So, spelling and pronouncing it wrong is actually a bit more natural as long as you aren’t submitting it as homework.