-을걸
-을걸: Guess Against Expectation — or Mild Regret
Spoken ending: guess differing from expectation, or mild regret about an undone action.
How to form it
| When | Form | Example |
|---|---|---|
| Batchim stem | -을걸 | 먹을걸 / 좋을걸 |
| Open stem | -ㄹ걸 | 갈걸 / 할걸 |
| Polite | -을걸요 | 좋아질걸요 / 비가 올걸요 |
-을걸 is a spoken ending with two clear dictionary jobs — do not flatten it to English I bet only.
Curriculum gloss: I bet — a guess you are fairly confident about. 우리말샘 -을걸 「001」: in casual speech, the speaker’s guess differs from what the listener already knows or expects — light rebuttal or exclamation. 「002」: mild regret about something you did not do (should have…).
Two colours
Guess / pushback (「001」)
비가 올걸요.
그 영화 재미있을걸.
지금은 닫았을걸요.
운동하면 체력이 좋아질걸요.Mild regret (「002」)
미리 말할걸.
어제 쉴걸.
좀 더 연습할걸.Same ending shape; tone and context pick the sense.
Forms
| Stem | Shape |
|---|---|
| Batchim | -을걸 |
| Open | -ㄹ걸 |
| Polite | -을걸요 |
Dictionary lists the batchim path after non-ㄹ stems and after -었-.
Neighbours
| Form | Lean |
|---|---|
| -을걸(요) | spoken ending (guess≠expect / regret) |
| -을 것 | nounish future/guess frame |
| -겠- | conjecture / intention ending family |
| -나 보다 | evidence-based inference |
When to use it
Use -을걸요 in casual talk for a soft spoken prediction or a light “actually I think otherwise.”
Use the regret reading when the line is I should have… about an undone action.
Skip it in formal notices — pick written guess tools instead.
Do not confuse it with
Taught alongside this
On the jabi learning path, this appears in 운동을 하면 체력이 좋아질걸요 (If you exercise, your physical strength will improve.) — Intermediate Korean 2, Unit 14, on the theme of body and exercise. These come with it:
Words used above
Quick check
No sign-up, no score saved — just see if it stuck.
1. Dictionary -을걸 「001」 leans toward…
2. 「002」 sense?
3. vs -을 거예요?
Common questions
Unit title 좋아질걸요?
Classroom soft prediction. Dictionary 「001」 frames guess against expectation — learn both the drill line and the dictionary colour.
Formal writing?
Marked 구어체. Prefer other guess tools in essays.
Past?
-었을걸 appears for past-oriented guess/regret. Meet it in input.
vs -나 보다?
neunga-boda leans inference from signs. -을걸 is a sentence-final spoken package.