INT 10 | ~던 + Noun

MEANING

~더~   Retrospective suffix (ex: ~던데: ~더+ (으)ㄴ/는데 refuting with the recalled memories)
+ ~(으)ㄴ Noun-modifying form (verb past / adjective present or past)
= ~던: describing a noun with recalling and reminiscing memories about it

CONJUGATION

Past tense suffix ~았/었~ + 던:

= same usage as the regular past tense noun-modifying form ~(으)ㄴ
= extra nuance of recalling the past memory: comment about that memory follows

먹었어요 ate	→ 먹었던 + N: N that SUB ate	= 먹은 + N
갔어요 went	→ 갔던 + N: N that SUB went to	= 간 + N
했어요 did	→ 했던 + N: N that SUB did	= 한 + N
살았어요 lived	→ 살았던 + N: N that SUB live	= 산 + N (ㄹ drops)

The restaurant we went last Christmas + was really good.
작년 크리스마스에 갔던 식당 + 진짜/너무/엄청 좋았어요.
= 작년 크리스마스에 간 식당 + 진짜/너무/엄청 좋았어요.

Dictionary stem + 던:

Incomplete action

~았/었~ also indicates completion of an action. Without the past suffix, the action was not complete

내가 먹던 우유 못 봤어?
Did you not see the milk I was drinking? (I didn’t finish it)

그거 내가 먹던 거야.
It’s the thing I was eating. = I was eating that. (Maybe you don’t want to eat it!)

~던 중 + 이다: in the middle of ~ing (Your friend walks in)
친구: 뭐 하던 중이었어? What were you in the middle of doing?
나: 식당 찾아보던 중이었어. I was in the middle of looking for a restaurant.

~던 길: on the way of going/coming
SM 에 가던 길에 레드벨벳이랑 엑소를 만났어요!
On the way to SM Entertainment, I ran into Red Velvet and EXO!

집에 오던 길에 사고 난 걸(=거를) 봤어요.
On the way of coming home, I saw that an accident happened.

Repetitive, habitual, continuous past action

You are recalling the middle of repetitive action that was done more than once

살다 to live                    여기가 제가 살던 집이에요. [live: continuous]
This is the house I used to live.
있다/없다 to exist/not    여기에 있던 식당 어디 갔지? [exist: continuous]
Where did the restaurant that used to be here go?
다니다 to attend (school/work)       제가 다니던 학교는 작은 학교였어요.
The school I used to attend was a small school.
키우다 to raise (kid, animal, plant) [사진을 보면서] 제가 키우던 강아지예요.
[Looking at a pic] This is the puppy I had.