eoje ilgdeon soseoreun chaekgalpireul kkoja dugo nawasseo.

I left the novel I was reading yesterday with a bookmark in it.

Breakdown of eoje ilgdeon soseoreun chaekgalpireul kkoja dugo nawasseo.

• 읽다: to read
• ~를: object particle
• ~은: topic particle
• 어제: yesterday

Questions & Answers about eoje ilgdeon soseoreun chaekgalpireul kkoja dugo nawasseo.

What does 읽던 mean here?

읽던 is the noun-modifying form of 읽다 with -던, which points to an action that was ongoing, repeated, or unfinished in the past.

So 어제 읽던 소설 means something like:

• the novel I was reading yesterday
• the novel I had been in the middle of reading yesterday

The key nuance is that the reading was not simply treated as a completed event. It feels like the speaker is referring back to something they were engaged in.

Why is it 읽던 소설 instead of 읽은 소설?

This is a very common question.

• 읽은 소설 = the novel that I read
  This sounds more like the reading is completed.
• 읽던 소설 = the novel I was reading / had been reading
  This suggests an ongoing or unfinished action in the past.

In this sentence, the speaker put in a bookmark and left, so the idea of not being finished yet fits very naturally. That is why 읽던 is a better choice than 읽은 here.

What is the difference between 읽던 and 읽었던?

Both refer to the past, but the nuance is different.

• 읽던 often emphasizes that the action was in progress, habitual, or unfinished at that past time.
• 읽었던 often sounds more clearly like a past experience or something completed in the past and now being recalled.

So:

• 읽던 소설 = the novel I was reading
• 읽었던 소설 = the novel I used to read / had read

In this sentence, 읽던 is more natural because the bookmark shows the speaker planned to continue reading later.