Core Grammar Rule: ~던
The particle ~던 is a retrospective adnominal ending. It attaches to verb stems to modify a following noun, indicating that the action or state was repeated, habitual, or continuous in the past.
Meaning & Usage
Meaning: It translates to "used to" or "would" and is used to reminisce about past events, habits, or states that are no longer happening. It implies that the action was either ongoing for a period or happened multiple times.
When to use: Use it when you want to recall something from the past with a sense of nostalgia or to contrast the past with the present. For example, talking about a school you "used to attend" (다니던 학교) implies you don't attend it anymore.
Conjugation Rules
Rule: Simply attach ~던 to the stem of any verb or adjective, regardless of whether it ends in a vowel or a consonant.
Verb/Adjective Stem + ~던
Synonyms & Differences: ~던 vs. -(으)ㄴ vs. -았/었던
These three forms all modify nouns with a past meaning, but they carry different nuances about the completion and continuation of the action.
~던 (Repeated/Unfinished Action)
Context: Use ~던 for an action that was done repeatedly or habitually in the past, or for an action that was in progress but was not completed. It emphasizes the process or the recurring nature of the event.
Example: 제가 읽던 책이에요. (This is the book I was reading / used to read.) This implies either you read it multiple times or you were in the middle of reading it.
-(으)ㄴ (Completed Action)
Context: Use -(으)ㄴ for a past action that was completed and is finished. It focuses on the result or the simple fact that the action happened once and was concluded.
Example: 제가 읽은 책이에요. (This is the book I read.) This implies you finished reading the entire book.
-았/었던 (Recalling a Specific, Completed Past Event)
Context: Use -았/었던 to recall a specific past experience that is completely over and has no connection to the present. It often carries a stronger sense of nostalgia or distance from the event than -(으)ㄴ.