~(으)ㄴ/는지 (~eun/neun-ji) – whether or not…
~(으)ㄴ/는지 is used in conjunction with interrogative/questioning words like 왜 (why), 어디 (where), 언제 (when), 뭐 (what), 누구 (who), 어떻게(how).
We see ~(으)ㄴ/는지 used in many sentences, spoken or written very often. ~(으)ㄴ/는지 is often used together with 모르다 as well, which means “don’t know whether or not…”
Sometimes we would see ~(으)ㄴ/는지 used together with 알다, which is usually expressing a question like “do you know whether or not..?”
Effectively, whether we attach ~(으)ㄴ/는지 with 모르다 or 알다 (see what I did there?), doesn’t really matter.
As shown in the sentence above, ~(으)ㄴ/는지 can be used in situations where there is a choice between two or more things. More in the example sentences later.
For verbs, we strictly use ~는지 for present and past tense while ~(으)ㄹ지 for future tense.
For adjectives, we will use ~(으)ㄴ지 for present tense, ~는지 for past tense and ~(으)ㄹ지 for future tense.
그 학생은 왜 자꾸 자는지 모르겠어.
I don’t know why that student keeps sleeping.
우리 강아지는 어디 가는지 모르겠어.
I don’t know where my puppy is going.
비가 언제 그치는지 모르겠어.
I don’t know when the rain is stopping.
사실 나는 지금 뭐 먹는지 모르겠어.
To be honest, I don’t know what I am eating now.
지금 누구 외치는지 모르겠어.
I don’t know who is shouting right now.
김치찌개를 어떻게 만드는지 모르겠어.
I don’t know how to make kimchi stew.
이 길은 회사로 갈 수 있는지 모르겠어.
I don’t know whether I can take this road towards the workplace or not.
오늘밤에 잘 잘지 모르겠어.
I don’t know whether I will sleep well tonight or not.
아까 고양이 잤는지 알아?
Do you know whether the kitten slept or not just now?
이따가 소개팅 할 여자는 예쁜지 모르겠어.
I don’t know whether the lady I’m going to meet for a blind date later is pretty or not.
이 약을 먹으면 몸이 괜찮을지 모르겠어.
I don’t know whether my body will be fine or not if I eat this medicine.
중학 시절에 먹었던 떡볶이가 맛있었는지 기억이 안 나.
I don’t remember whether the spicy rice cakes that I used to eat during my middle school days were delicious or not.