V+ 을/ㄹ 걸 괜히 V+ 었다/았다/였다

It is used when you regret choosing the second behavior but not the one mentioned first.

For ‘-을/ㄹ 걸’, if the stem of the action verb ends with a vowel or ‘ㄹ’, you use ‘-ㄹ 걸’, if it ends with another consonant, you should use ‘-을 걸’.

For ‘-었다/았다/였다’, if the last letter of the action verb ends with ‘ㅏ, ㅗ’, you use ‘-았다’. If it ends with other vowels (ㅓ,ㅜ,ㅡ,ㅣ), you use ‘-었다’, and if it ends with ‘하-‘, you use ‘-였다(했다)’.

길이 너무 막히네요. 지하철을 탈 걸 괜히 버스를 탔어요.
The road is too congested. I should have taken a subway, too bad I took a bus.

저녁에 외식을 할 줄 알았으면 과자를 먹지 말 걸 괜히 먹었어요.
If I knew we would go out for dinner, I should have not eaten the snack, too bad I ate it.

운동화를 신을 걸 괜히 구두를 신고 나왔네요. 너무 발이 아파요.
I should have worn sneakers, too bad I wore my shoes. My feet hurt so much.

Conversation:

흐엉 씨가 시킨 짬뽕은 맛이 어때요? 먹을 만해요?
What does the jjamppong Huweong order taste like? Is it worth eating?

생각보다 더 매콤한 것 같아요. 볶음밥은 어때요?
I think it’s more spicy than I thought. How about the fried rice?

맛이 괜찮아요. 한 입 먹어 보실래요?
It tastes pretty good. Would you like to have a bite?

먹어 보니까 볶음밥이 훨씬 제 입에 맞는 것 같아요.
Now that I’ve tried it, I think fried rice is better for my taste.

저도 볶음밥을 시킬 걸 괜히 짬뽕을 시켰네요.
I shouldn’t have ordered a jjamppong but instead, I better had fried rice.

짬뽕이 너무 매우면 다른 음식을 하나 더 시키실래요?
If jjamppong is too spicy, would you like to order another food?

못 먹을 정도는 아니에요. 그냥 이거 먹을게요.
It’s not that I can’t eat. I’ll just eat this.

사실 제가 아까부터 속이 좀 더부룩해서 다 못 먹을 것 같은데 좀 덜어 드릴까요?
Actually, I’ve been feeling a little bloated from a while ago and I don’t feel like I can eat all of it. Do you want me to give you some?

Related words
매콤하다 to be spicy
더부룩하다 to feel bloated
덜다 to spare
외식 eat out, dine out