A, V- 거든요, Korean grammar Intermediate

Usage:

A, V- 거든요  This expression is used to respond to a question or to add to a statement the speaker has already made to provide the reason or thinking behind the answer or statement. The listener has no knowledge of the reason or facts being stated by the speaker. Note that the form - 거든요 is used only in conversation, not in writing Korean. Moreover, it is only used among close friends or those on familiar terms with each other. It is not used in formal situations, such as when giving a presentation. 

Tense:

Conversation 1 

가: 자야 씨, 오늘도 이 식당에 가려고요?

나: 네, 여기가 정말 맛있거든요.

마크 씨도 같이 갈래요?

A: Jaya, are you planning to go to this restaurant again today? 

B: Yes, (because) this place has really good food.

Do you want to go, too, Mark?

Conversation2 

가: 오늘 왜 그렇게 피곤해 보여요?

나: 어제 영화를 보느라고 잠을 못 잤거든요.

A: Why do you look so tired today?  

B: I didn't get a lot of sleep yesterday (because I was) trying to

watch a movie.

   More example:

1. 

가: 제주도에 갔을 때 한라산에 올라가셨어요?

나: 아니요, 못 갔어요. 날씨가 안 좋았거든요.

A: Did you go up Mt. Halla when you went to Jeju Island?

B: No, I didn't. (Because) the weather was bad.

2.

가: 피곤하실 텐데 오늘도 요가를 하러 가시는 거예요?

나: 네, 요가를 하고 나면 몸이 가벼워지거든요. 그래서 피곤해도 요가를 하러 가요.

A: You must be tired, and yet you're going to yoga class? 

B: Yes, (because) I feel so relaxed after yoga class. So I go to yoga class even when I'm tired. 

3.

가: 요즘 비가 정말 자주 오네요.

나: 요즘 장마철이거든요. 한 달 동안은 계속 올 거예요.

A: It's really been raining a lot recently. 

B: (You see,) it's currently the rainy season. It will rain for a full month.